In the history of Christian missions to the Muslim world only one man has been recognized with the honorary title, “the Apostle to Islam”. Samuel Marinus Zwemer (1867-1952), a man whose name was synonymous with missions in Arabia, has seemingly been forgotten in the twenty-first century. According to Warren Larson, former director of the Samuel Zwemer Center for Muslim Studies at Columbia International University, “Samuel Zwemer was the greatest missionary ever sent to the Muslim world.” Such a legacy of surrender, sacrifice, and service must be resurrected from the archives of the history of Christian missions and publicized throughout Christian organizations that are committed to the Great Commission.
Zwemer’s tireless efforts in evangelizing Muslims, rallying support for missions in Arabia, motivating missionaries, prolific writing and editing, and, later, his teaching at Princeton all had a dramatic influence on countless Christian missionaries who surrendered to the call to the Muslim world. The impact of Zwemer’s life cannot simply be weighed by the number of books or articles he published, nor can it be graded on his thousands of sermons, lectures, and speeches. The measure of a man so committed to the Great Commission may never fully be known. Only in eternity will one truly recognize how far reaching Zwemer’s impact was on the evangelization of the Muslim world. A life so committed to proclaiming the riches of Christ, in what was, and remains, the most challenging and difficult mission field, warrants a careful analysis, as well as a contemporary retelling. It is therefore the purpose of this article to provide a contemporary and abridged biography of the life and ministry of Samuel Zwemer. This article includes a synopsis of his early life and conversion, an examination of his call and ministry training, an overview of his work as a missionary, conference speaker, editor, author, and professor, and a summation of his final years.
Birth and Early Years
Samuel Marinus Zwemer was born on April 12, 1867 to Adriaan and Catherina (Boon) Zwemer in the parsonage of the Reformed Church of Vriesland, Michigan. His parents, both immigrants, had traveled to America from Holland to start a new life on the western frontier. The Zwemer’s were devote Christians who made sure their fifteen children received a thorough education. To their credit, all six of Adrian and Catherina’s daughters became schoolteachers, one of the girls, Nellie, spent nearly forty years as a missionary-teacher in China, and four of their boys entered vocational ministry. J. Christy Wilson offers a brief glimpse of the influence Adriaan and Catherina’s on the Zwemer boys writing,
The oldest brother, James Frederick, had a notable career, and, among other positions, he was president of Western Theological Seminary at Holland, Michigan. Frederick James Zwemer also was a minister and a pioneer evangelist in the Dakotas. Peter John Zwemer, who was a year and half younger than Samuel, followed his brother to Arabia. There the precious cruse of his strength was broken for the Master’s service after a few short years in the rocks and hills and awful heat of Muskat in the Persian Gulf. He was forced to return to America and died in the Presbyterian Hospital in New York on the eighth of October, 1898, just six weeks after his thirtieth birthday.
Samuel’s parents provided an environment where the seeds of the gospel took root and later sprouted into the conversion of their children to Christ. Moreover, their commitment to living missionally was on display for the Zwemer children. Adriaan was consumed with the burden that the gospel must be preached in the frontiers of America. In fact, he often relocated the family urging his wife and children to realize that if they did no go the new field may be neglected. Wilson comments that the numerous moves to new churches created in Samuel an adaptability that taught him to be at home anywhere. Adriaan’s impact on his son is felt in the words Zwemer later wrote in the dedication of his book, The Moslem Doctrine of God, “Yet must I thank thee, not for any deed, but for the sense they living self did breed, that Fatherhood is at the great world’s core.” Catherina, the faithful wife and mother, always made time to minister to the needs of others. Samuel remembered his mother as godly woman who was always busy serving others with her hands and her heart. Before her passing, she told Samuel that “she had dedicated him to the Lord’s service and paled him in the cradle with a prayer that he might grow up to be a missionary.” Catherina would not live to see the great extent to which God answered her prayers. However, Samuel Zwemer’s legacy is a continuation of the missionary zeal and dedication of his parents.
College, Calling, and Seminary
Zwemer, the thirteenth of fifteen children, grew up in a home where major decisions were made after seasons of prayer and the Bible was read at every meal. Although he had been saturated with the teachings of Scripture and had sat under the preaching of the gospel, it was not until after he had entered Hopewell College on March 9, 1884, that Zwemer officially joined a church. When asked about his conversion, he testified that he felt that he had accepted Christ as a young man and could not remember a time when he was not a Christian.
It was during Zwemer’s senior at Hope College that he heard Robert Wilder speak on the pressing need for pioneer missionaries on the foreign fields. Wilder was the founder of the Student Volunteer Movement, an organization that sent approximately fourteen thousand students to overseas mission fields. Wilson records this event in vivid terms,
While he [Robert] was presenting the needs of missions, he had a map of India on display with a metronome in front of it. It was set so that each time it ticked back and forth one person in the Indian subcontinent died who had never heard the gospel of Jesus Christ. This so affected Samuel Zwemer that at the end of the message he rushed forward and signed the decision card, which stated: “God helping me, I purpose to be a foreign missionary.”
Zwemer was so moved by Wilder passionate pleas for young men and women to volunteer as overseas missionary that he quickly became ardent supporter and leader in the movement. The motto “The evangelization of the world in this generation,” characterized the passion and zeal that was taking root across Christian campuses. Zwemer, who embodied this zeal, committed his life to preach the gospel in places and to people who were not only lost, but extremely zealous about their opposition to Christianity.
In September 1887, Zwemer begin the next phase of his ministerial training at the Theological Seminary of the Reformed Church in New Brunswick, New Jersey. It was during his time in Seminary that God providentially placed two important people in Zwemer’s life. Professor John G. Lansing, a Hebrew professor at the seminary and who had spent years in the Middle East and Egypt, became an adviser and close friend to Zwemer. Along with Lansing, Zwemer met James Cantine, a like-minded student who had a burden to plant the gospel in a field that desperately needed it. Together, Zwemer and Cantine agreed that they would preach the gospel in the heart of the Muslim world and adopted a motto based on the prayer of Abraham in Genesis 17:18, “O that Ishmael might live before you!” James Cantine graduated in 1889, a year before Zwemer, and went on to Beirut to study Arabic. Before he left, the students presented him with a pair of binoculars, which Samuel said were appropriate as he was going “to spy out the land.” Zwemer completed his seminary work and graduated with honors, receiving his B.D. degree and went on to be ordained in the Reformed Church of America on May 29, 1890.
Missionary in Arabia
Feeling compelled to preach the gospel in the birth place of Islam—the Arabian Peninsula—Zwemer appealed to the Reformed Church to support his endeavor. At that time, the denominational leaders did not believe that they could financially support the new work. This response prompted Zwemer to declare, “If God calls and no board will send you, bore a hole through the board and go anyway.” Throughout his life, Zwemer would continue to be characterized as both a trailblazer and as man who was utterly dependent upon the power of the Holy Spirit. An elderly woman who had once stayed with the Zwemer’s stated, “I lived for several months with the Zwemers, and I know where Sam gets his strength, he drinks form the hidden springs.” She was referring to the Zwemer’s habit of each day spending an hour in prayer. His commitment and steadfastness to his mission was only made possible by his fervent prayer life. Believing that God had called him and being fully convinced of the power of the gospel, Zwemer would not let anything or anyone prevent him from preaching the gospel in the Muslim world.
In several ways, Samuel Zwemer was a pioneer in missions. While he was certainly not the first missionary to the Muslim world, he had few equals concerning his knowledge of Islam. His understanding of the Muslim religion, however, was never an end but a means to preaching the gospel. Every aspect of Islamic theology was analyzed by Zwemer in order to present the truth claims of Christianity. Nowhere is this so evident than in his critique of the Muslim view of Muhammad. He writes,
The preexistence of Christ is everywhere denied. While Muslim tradition is full of stories about the light of Mohammad, created before all things and existing before all worlds. It seems incredible that Islam, while imputing to Mohammed that which he never asserted of himself, namely, preexistence, should deny this in connection with Jesus Christ.
Zwemer’s approach to evangelism integrated an appreciation and understanding of Islam with an unwavering commitment to the proclamation of the gospel of Jesus Christ. He refused, however, in personal evangelism to openly attack Islam or its founder. When asked about his method, he responded, “We decided never to attack Islam or the religion of anyone present, but state positively the claims of Christ and invite them lovingly to accept him as Lord of their life.” When asked how he answered Muslims who asked him what he thought of the founder of Islam, he replied, “I consider Muhammad the greatest Arab to have ever lived and next to the New Testament he gave the greatest witness to Jesus Christ. Then I should point them to the place where the Qur’an calls Christ the ‘Word of God.’” In his contextualized approach, Zwemer was not endorsing or validating Islam or the Qur’an. His goal, however, in referring to the Qur’an was to find common ground upon which he could declare the glorious gospel of Jesus Christ.
The gospel of Jesus Christ “is a message of salvation,” wrote Zwemer in the forward to his book on evangelism. He continues by asserting that the gospel “is of God and not of man.” These statements demonstrate that Zwemer was not interested in merely having an inter-religious dialogue with adherents of Islam, but that he was fully convinced of the nature and power of the gospel. Moreover, he argued convincingly that the method or technique in evangelism was secondary to the message. He writes, “Christ has called us to be fishers of men. We will not progress far by forsaking all hooks and nets to feed the hungry fish in their own environment. Peter on Lake Galilee and Isaac Walton in his Compleat Angler laugh such fisherman to scorn.” For Zwemer, evangelism was the proclamation of the death, burial, and resurrection of Jesus for those who would, by faith, repent of their sins and trust in the atoning work of the Son of God.
The character of Zwemer was most vividly displayed in his willingness to preach in the most difficult mission field in the world, Arabia. Wilson writes that Zwemer had decided to “apply the antidote of the Christian gospel at the very source, where the Mohammedan religion saw its birth, where its adherents were most fanatical, where there was little hope of numerical success in converts, and where the climate was all but impossible.” Convinced that all Christians were called to take the gospel to places where the need was great, Zwemer celebrated the notion that one did not need a special call to go to the foreign field, but a special call to stay in a country where the need was not so great.
His first missionary tour would span over two decades and began with the founding of the Arabian mission station in Bahrain, an island halfway down the Arabian coast. Since the name Samuel did not appear in the Qur’an it was difficult to pronounce in Arabic. Thus, Zwemer decided to refer to himself as Dhaif Allah, or the guest of God. Some of the more antagonistic Muslims, according to Cloer, would intentionally mispronounce this Arabic name to translate as “guest of Satan.” However, Zwemer quickly established himself among the locals by distributing Bibles and conversing with Muslims in the marketplace. Thankfully, he was not alone in this effort. Wilson writes that in the same year his younger brother Peter joined the mission and opened a substation at Muscat. Zwemer and his colleagues encountered opposition in Bahrain; however, they would not be deterred by either the climate or the lack of converts. Due to Zwemer’s dedication and perseverance, in 1894 the Reformed Church officially adopted the Arabian Mission.
Never free from the threat of danger, disease, or even death, Zwemer was a man who lived as if each days was his last. In a letter to his sister Nellie, he recalls the challenges of his work. He wrote,
On the way we had a heavy hail and thunder storm that filled all the wadies, swept away the donkey of our guide and when the camels stampeded I lost my umbrella and part of my outfit! It was the worst storm in which I ever had to sit under a bush! At night we found a house. The next day all my books were seized at the Customs, in spite of every effort I could only get back Sprenger and the German authority as guides. All the rest were declared ‘forbidden.’
Later in the same letter, he provided details of just how challenging it was for a missionary to travel throughout the Muslim world. He wrote,
At Taiz I waited in a dirty coffee shop 15 long weary days on the red tape government. One soldier who was sent for my books was attacked on the road, stabbed, and robed of his rifle! While at Taiz I tried to preach a little bit but a mob went to the governor’s house and demanded my expulsion. I was warned not to speak to any Arab under penalty of being sent a prisoner to the coast. At the first station Ibb my servant was put into jail because he gave me the name of some villagers en route to me! No adventure after that up to Sana’a except that a poor Jew with whom I tried to speak was beaten and cursed because he ventured near the guard. At Sana’a I obtained liberty through my passport. But I believe I am very closely watched . . . Have read over 2/3 of my English Bible on route, not a bad job for a vacation.
To say that opposition and obstacles were a regular occurrence for Zwemer would be an understatement. Summarizing Zwemer’s perseverance in the midst of such obstacles, Wilson records a description of him as a man who possessed the ideal qualities of a missionary. He writes, “A Dutch-American like this young fellow, with a good Arab tongue in his head, is not easily daunted. It is quite true that one who combines the stubbornness of the Dutch and inquisitive American Spirit, the zeal of a pioneer for Christ is not easy to stop.”
During his tenure in Arabia, Zwemer encountered both joy and tragedy. On May 18, 1896, he married Amy Wilkes, a nurse and missionary from Australia whom he had been assigned to as an Arabic teacher. Within a few years the Zwemers were blessed to become parents, not once but twice. Shortly after starting his family, however, he would suffer the loss of his brother Peter and, a few years later, his two children who died of dysentery. In an amazing testimony to the fortitude and devotion of the Zwemers, they had inscribed on the headstone of their two young daughters, “Worthy is the Lamb to receive riches.” It would have been easy to turn back from the call to preach in Arabia, but the Zwemers stayed the course and continued the work.
Zwemer’s vision was not limited to Arabia. His willingness to speak far and wide about the current state of missions among Muslims and the vast scope of his journeys demonstrated that he had a burden to take the gospel to the entire Muslim world. In a day when traveling great distances was done primarily by boat or train, and, in Zwemer’s case, by camel, his travels included trips to Europe, India, China, Indonesia, North and South Africa, as well as countless places throughout the Middle East.
On his first furlough, Zwemer received offers from the Reformed Board of Foreign Missions and The Student Volunteer Movement to serve as field secretary and recruiter. Unable to decide between the two, he accepted both offers and simultaneously raised money and recruited missionaries for the Middle East. His approach was always the same; He would press upon the audience the urgent need of the gospel in the Muslim world and call for Christians to join him on the field. One example of his appeal was heard on January 22, 1911, while speaking to the delegates of the Lucknow conference, he said, “The supreme need of the Muslim world is Jesus Christ. He alone can give light to Morocco, unity in Persia, life to Arabia, re-birth to Egypt, reach the neglected in China, win Malaysia, meet the opportunity in India, and stop the aggressive peril in Africa.”
After accepting the dual appointments of the Reformed Foreign Mission Board and Student Volunteer Movement, Zwemer’s ministry would, until his death in 1952, include an impressive conference speaking schedule. Even after returning to the foreign field in 1912, Zwemer traveled all over the Muslim world rallying support, lecturing on Islam, and, wherever he could find Muslims, distributing Bibles and gospel literature. His efforts as a missions conference speaker likely had a greater impact than any of his work on the field. In a concise synopsis of Zwemer’s efforts, Wilson writes,
A great part of Zwemer’s time . . . was spent speaking at conventions. He was largely responsible for the first General Conference of Missionaries to the World of Islam, held in Cairo in April 1906. This was sponsored by mission boards with work in Muslim countries. His effectiveness was never more evident than at the quadrennial conferences of the Student Volunteer Movement. Zwemer hung a great map of Islam before and, with a sweep of his hand across all those darkened areas, said: ‘Thou Oh Christ art all I want and Thou Oh Christ art all they want. What Christ can do for any man, He can do for every man.’ [Robert] Speer and Zwemer probably influenced more young men and women to go into missionary service than any two individuals in all of Christian history.
Zwemer was never celebrated as an evangelist who won scores of Muslims to Christ, but he was widely known as a missionary who served in the trenches while passionately challenging others to join him on the front lines. His efforts to educate Christians about the need in the Muslim world was complemented by his long list of publications.
Missionary in Egypt
Zwemer’s vision of evangelization of Muslims was always bigger than Arabia and included the entire Islamic world. After a brief return to the United States, the call to the foreign field was too strong and Zwemer returned to the Muslim world in 1912. This time, however, he would not return to the birthplace of Islam. Instead, he would continue his work in the intellectual capital of Islam, Cairo, Egypt. There he would serve, in part, through the American University of Cairo. Believing that the printed page was an extremely effective and lasting means of evangelizing Muslims, Zwemer zealously published and distributed gospel literature. In an incident at one of the world’s leading Islamic schools, Al-Azhar University of Cairo, Zwemer, who was distributing gospel pamphlets to Muslim students, had so enraged one professor that he reported the evangelist to the local authorities. Zwemer was subsequently asked to leave the country, which he did only to return two weeks later.
The Princeton Professor
After serving in North Africa for nearly seventeen years, Zwemer began the third stage of his ministry as a professor at Princeton Theological Seminary. The local press provided what would be a fitting summary of his time in Cairo referring to Zwemer as the leading authority on Islamics from the Christian standpoint.” Zwemer who had blazed a trail into both the heart (Arabia) and head (Egypt) of the Islamic world, retired from field work to train the next generation of Christian missionaries.
The decision to join the faculty of Princeton Theological Seminary in 1929 was deemed by Zwemer as “The Third Milestone.” The first milestone was two decades in Arabia, and the second his seventeen years in Egypt. Now, he was joining an institution that had a legacy of sending foreign missionaries from nearly every graduating class. Wilson observes that “for more than a century a portion of every class but three had gone to the foreign field for missionary service and more had entered such service from this seminary that any other.”
On October 1, 1930, Zwemer gave his inaugural address as the newly appointed Professor of the History of Religion and Christian Missions in Princeton Theological Seminary. His speech was entitled, “The Place of the History of Religion in a Theological Discipline,” provides three justifications for the study of non-Christian religions by Christian theologians and missionaries. He proclaimed that,
- Only a Christian theologian can rightly understand and interpret the history and character of the other religions.
- The History of Religion as a discipline lies at the basis of Christian apologetics over against the non-Christian world.
- The study of non-Christian religions and the application of the Holy Scriptures to that study will lead to a deeper understanding of the distinctive doctrines and spirit of Christianity and a conviction that Christ is the only hope of the world—that Christianity is therefore the final and absolute religion.
Zwemer was convinced that contact with other religions, and especially with Muslims, would force Christians to think through and clarify their beliefs on important doctrines such as the trinity. A Christian missionary who was unfamiliar with the beliefs of Islam, or any other religion for that matter, was not fully prepared for the foreign field.
Throughout his tenure at Princeton, Zwemer primarily taught courses on the history of religion and Christian missions. His courses were filled with personal anecdotes and vivid illustrations from his forty years on the foreign field. Serving as a professor, however, would not slow down the man whom God had called to preach the gospel. In his typical missionary form, Zwemer’s home was always open to students and neighbors, alike. Furthermore, he would go out of his way to frequent many of the local business in order to evangelize the members of the surrounding community. Nothing, not even a distinguished chair in a prestigious institution, could keep him from traveling the world to herald the need of missionaries to the Muslim world.
After retiring from Princeton, Zwemer, demonstrating his sense of humor, stated that he was doing so to go into “active service.” The truth is that he had never ceased to be active in evangelizing unbelievers and encouraging Christians to do likewise. Evangelism and missions were not part of Zwemer’s life, they were at the crux of his existence. His retirement from Princeton neither ended nor hindered his ministry, because from the time of his calling to the end of his life, Zwemer never ceased to declare the amazing grace of God.
The Editor and Author
Samuel Zwemer was a prolific writer and is accredited with more than fifty publications. According to Larson, “It is impossible to know how many books, articles, and other publications that Zwemer produced because he published writings in English, Dutch, and Arabic.” In addition to writing countless books and numerous articles, for over forty years he served as the editor of The Moslem World, a quarterly journal that he founded in 1911.
As the editor of The Moslem World, Zwemer was able to teach Christians about the various beliefs and practice of Islam, and encourage them to send and support missionaries to the Islamic world. These editorials provide a glimpse into the heart of man who was both critical of Islamic doctrine and, at the same time, loved Muslims. For example, he wrote, “Islam is, in a sense, the only anti-Christian religion.” He continues in true Zwemer fashion, “Our love for them [Muslims] is only increased by our intolerance of their rejection of Christ; we cannot bear it, it pain us.”
His Final Years
It was Princeton’s policy, at the time, that faculty members had to retire at the age of seventy. This rule, however, did not slow Zwemer down. Throughout his final years, he continued to preach and speak on missions. Up to the very end, his priority was challenging the church to take the gospel to Muslims. Wilson provides a fitting description of Zwemer, “It was a life ever vibrant, filled with the power of the Holy Spirit. It was the life of a joyful crusader in a great cause—the greatest cause—down to the last day.” Likewise, another biographer wrote, “An entrepreneurial spirit, coupled with enormous faith, vision, and energy, characterized [him] throughout his life.”
From his early years as a student at Hope College through his years proclaiming Christ in the Muslim world, Zwemer was a committed evangelist and champion of the cross. Moreover, he was a man called by God to announce to the church the desperate need for the gospel in the Muslim world. Like the Apostle Paul, who told the Church at Colossae that he worked to exhaustion and agonized in order to proclaim Jesus Christ (Col 1:28-29), the “Apostle to Islam” was motivated by a love for Muslims that drove him to work tirelessly in order that they too would be gathered to Christ. He wrote, “Real Christians are the best and truest friends of Muslims everywhere and always.”
Latourette, Kenneth Scott in the Introduction to J. Christy Wilson, Apostle to Islam: A Biography of Samuel M. Zwemer (Grand Rapids: Baker Book House, 1952), 5, “No one in the centuries of Christian missions to the Muslims has deserved better than Dr. Zwemer the designation of Apostle to Islam.”
Warren Larson, statement made during a phone interview by author, May 5, 2014.
The Great Commission is written five times in the New Testament: Matt 28:18-20; Mark 16:15-16; Luke 24:46-49; John 20-21; and Acts 1:8.
There are innumerable untold stories of Christians who have made the ultimate sacrifice to bring the gospel to the Muslim world. Countless men and women have abandoned the safety and comfort of the Christian West and set out to take the good news of Jesus Christ to the unbelieving Muslim world to never return. Additionally, a great number of missionaries have and continue to faithfully evangelize people groups among predominately Muslim populations. While Samuel Zwemer, in many respects gave far less than many of these saints, and even though he was not martyred for his Christian faith, he, nonetheless, paved the way for all who would follow the call to preach the gospel to the Muslim world.
Even though many have included some information about the life and ministry of Samuel Zwemer in their writings. Only one significant biography exists about the life and ministry of Samuel Zwemer, Wilson, Apostle to Islam In addition, several master theses and doctoral dissertations have been written on or included biographic information; Yohannes Bekele, “Samuel Zwemer’s Missionary Strategy to Islam” (The University of Birmingham, 2012); Clayton Parnell Cloer, “Samuel Zwemer: A Model of Muslim Contextualization” (Mid-America Baptist Theological Seminary, 2000); Peter Ipema, “The Islam Interpretations of Duncan B. MacDonald, Samuel M. Zwemer, A. Kenneth Cragg and Wilfred C. Smith: An Analytical Comparison and Evaluation” (The Hartford Seminary Foundation, 1971).
Roger S. Greenway, ed., Islam and the Cross: Selections from “The Apostle to Islam” Samuel M. Zwemer (Phillipsburg, NJ: P & R Pub., 2002), xi.
Wilson, Apostle to Islam, 22.
J. Christy Wilson, Flaming Prophet: The Story of Samuel Zwemer (New York: Friendship Press, 1970), 10.
Samuel M. Zwemer, The Moslem Doctrine of God: An Essay on the Character and Attributes of Allah according to the Koran and Orthodox Tradition (Boston, NY: American Tract Society, 1905), 5.
Wilson, Flaming Prophet, 9.
Wilson, Apostle to Islam, 21.
Greenway, Islam and the Cross, xii, presents this date as the day on which Zwemer became a Christian. Wilson, Apostle to Islam, 28, does not list this date as Zwemer’s conversion, but as the day he joined the church.
Wilson, Flaming Prophet, 11.
J. Christy Wilson Jr., “The Apostle to Islam: The Legacy of Samuel Zwemer,” International Bulletin of Missionary Research, July 1986, 117.
William M. Miller, A Man Sent From God Whose Name Was Samuel (Philadelphia, PA: The Sunday School Times Foundation, 1966), 2.
All scripture references are from the English Standard Version of the Bible.
Wilson, “The Apostle to Islam: The Legacy of Samuel Zwemer,” July 1986, 118.
Greenway, Islam and the Cross, xii.
Wilson, Flaming Prophet, 15.
Greenway, Islam and the Cross, 5.
Wilson, Flaming Prophet, 86.
Samuel M. Zwemer, Evangelism Today: Message Not Method (New York: Fleming H. Revell Company, 1944), 7.
Wilson, Apostle to Islam, 39.
Samuel M. Zwemer, Into All the World: The Great Commission: A Vindication and an Interpretation (Grand Rapids, Mich.: Zondervan Pub. House, 1943), 199.
Cloer, “Samuel Zwemer: A Model of Muslim Contextualization,” 13.
J. Christy Wilson Jr., “The Apostle to Islam: The Legacy of Samuel Zwemer,” International Journal of Frontier Missions 13, no. 4 (December 1986): 165.
 Wilson, Apostle to Islam, 62.
Wilson, “The Apostle to Islam: The Legacy of Samuel Zwemer,” December 1986, 165.
Wilson, Apostle to Islam, 39.
 Ibid., 174.
 Wilson, “The Apostle to Islam: The Legacy of Samuel Zwemer,” December 1986, 165.
Wilson, Flaming Prophet, 53.
Wilson, “The Apostle to Islam: The Legacy of Samuel Zwemer,” December 1986, 166.
Wilson, Apostle to Islam, 92.
In 1918 Zwemer had spent a semester at Princeton teaching several courses on Christian missions. It quickly became apparent to Zwemer that he was not ready to retire from the field to the classroom. He decided therefore to return to Cairo to continue his work among Muslims.
Samuel M. Zwemer, “The Place of the History of Religion in a Theological Discipline,” The Princeton Seminary Bulletin, November 1930, 24 edition.
Through his years of engaging Muslims with the gospel and listening to their rebuttals, Zwemer became convinced that a clear presentation of the trinity was essential. He especially believed this was true in light of Muhammad’s misunderstanding of the trinity. He writes, “This trinity Mohammed misunderstood or misrepresented as consisting of Allah, Jesus, and the virgin Mary. Zwemer, The Moslem Doctrine of God, 29.
 Wilson, “The Apostle to Islam: The Legacy of Samuel Zwemer,” December 1986, 167.
Larson, Interview, May 1, 2014.
 Wilson provides a list of Samuel Zwemer’s book and the languages into which they were translated. He does not, however, provide a list of articles or papers by Zwemer. Wilson, Apostle to Islam, 251–53.
Samuel M. Zwemer, “Editorial,” The Moslem World 1, no. 2 (April 1911): 97.
Wilson, Flaming Prophet, 95.
Greenway, Islam and the Cross, xii.
Samuel M. Zwemer, “Editorial,” The Moslem World 2, no. 3 (July 1912): 225.