In the days when many Americans were first becoming aware of the larger religious world, Sailer introduced them to Islam. Reaching for an understanding of how the two religions relate, he begins this study with an introduction to the Muslim world. Sailer approaches the subject with a respect for Islam and its believers. Aiming to prepare missionaries for Muslim regions, he writes for a general readership. Understanding, he believes, begins with an overview of Muslim life and the character and influences on Islam. Designed as a short adult course on the subject, this booklet has instructions for the leader of an adult group on the topic. Interested in the impact of Christianity on Islam, Sailer explores what churches might do. Taken all together, this little booklet spells out a plan of action for what the author saw as a missionary opportunity.

Thomas Henry Powers Sailer (b. 1868) earned a Ph.D. and taught at Teachers College, later part of Columbia University. A Presbyterian interested in missions, he wrote widely on Christianity and Islam.