John is one of the first significant theologians to possess a fairly accurate knowledge of Islam based on firsthand familiarity with Islam's sacred texts. He correctly recalls important Islamic beliefs, such as the oneness of God, Jesus as the Word of God and a prophet, Jesus' miraculous birth, the denial of Jesus' crucifixion, the Qur'an as God's revelation to humanity, and so forth. A greater knowledge of Islam, however, does not make him a more benevolent interpreter of Islam. John's agenda is not to provide an impartial description of Islam but to assist Christians who, as dhimmis, need help in their efforts to survive the pervasive claims of Islam and to resist the impulse to convert. The more Christians can see Islam as a perversion of the Christian gospel, the better equipped they will be to maintain steadfastness in the faith.

Green, Todd H, The Fear of Islam_ An Intro…, loc. 132