Humanism is an intellectual doctrine, resulting from the age of enlightenment and renaissance. It emphasizes mans significance and centrality rather than God Almighty. This doctrine relies on empirical reason, rejecting all other cognitive tools. Therefore, it rejects metaphysics, and instead, it focuses of man’s personal freedom. Deism is a doctrinal situation that believes in God and that He is the Creator of the world, but it denies His relation with the world through revelation, mission and prophets. It sees that God has created the universe and left alone, without asking human beings to abide by faith or religion. In this article, we discuss the relationship between humanism and deism by showing the flaws and problems of both of these doctrines, which lead to a wrong view about the relationship between God and man, through the deification of man, abolition of the supremacy of God, and the denial of the prophets’ missions. In addition to that, we criticize absolute personal freedom that is not controlled by any restrictions or conditions. On the other hand, we show the true nature of religions in understanding the relationship between God and the world, and that centrality is for God Almighty. Moreover, the study assures the necessity of sending prophets with divine missions to nations, and that freedom must be controlled by the divine teachings. Finally, it is worth mentioning that the study has followed the critical, analytical approach.