Islam is one of the two greatest external threats to Christianity in the twenty-first century. Statism is the other. Though not as old as statism, Islam has been at war with Christianity since its inception by Mohammad in the seventh century. This booklet provides a brief overview of the history of Islam and its teachings in order to give proper context to this very grave danger that the free world and the Christian faith faces. The historical overview of Islam presented here-which includes the Crusades, important battles stopping Islam's spread throughout Europe, and Muslims' influence in American history-reveals that its aggressive expansion and conflict with Christianity are normal. The ideological and worldview comparison of Christianity and Islam shows that Christianity produces liberty, while Islam brings oppression. Many questions are also answered, such as: Is Islam a religion of peace? How should America deal with Islamic terrorists? What can we do regarding the threat of Islam to the Christian faith? Finally, there is good news: God is moving among many Muslims to bring them to Christ. Endorsement: "The Threat of Islam to Liberty and Christianity is a fine piece of scholarship that merits the widest distribution possible. It is a first rate summary of the history and interaction of Christianity and Islam. Your handling of the Crusades is the most succinct I have read anywhere, 'The Crusades were not the brainchild of an ambitious Pope or rapacious knights but a response to more than four centuries ... of Muslim conquests.'" - Gen. Jerry Curry (retired)