This article attempts to study, with a critical analytical approach, an important topic related to the question of the reality of religious faith. Faith is a voluntary heart inclination and belief, flowing from man’s knowledge and awareness. In spite of the close relation between faith and knowledge, its essence is still different from the essence of science and knowledge.This look to the reality of faith in the Islamic awareness differs from what is said about it in the Christian awareness. In the article, two viewpoints on faith are discussed in light of Christian culture. The first is the viewpoint of the faith in cases, represented by Saint Thomas Aquinas, and the second is the viewpoint of the Will Doctrine represented by William James. As for Islamic culture, the viewpoints about the reality of religious faith, adopted by the Mutazilites, the Asharites and the Twelver Shia, have been talked about. However, the Islamic look to religious faith came to be different from that in Christian awareness; hence, the two should not be considered the same in both cultures.