The importance of modernity is because of man's place as the axis of all beings and existents like God and the World, and they get their meaning and validity in the light of him. Although man has reason and freedom and he is the noble master of all creatures, in the meanwhile, he has many defects in his existence, and his accomplishments have been gradually increased during the centuries. Hence, we can say that man actually and absolutely does not have any perfection, and he cannot get his achievements perfectly. However, with changing in the relationship between man, God, and the world during the modernity age, the whole of man's approaches to God and the world changed, and this brings about some basic problems and crises. In this process, man gained and acquired a kind of genuineness and principality towards God and the existents of world that their place and importance, especially divine truths like God, were defined in the light of human epistemic abilities and their validity were depended on human knowledge. Hence, the place of divine truths was lowered to the limits of human understanding, which I call it the humanization of divine truths. On the other hand, because of his weakness for understanding the divine truths, man has gradually put them aside from his philosophical thought, and has recognized them meaningless. In the meanwhile, he has tried to understand the empirical world and its managing without considering what is beyond it. I call this demystification of the existents by the other areas such as ethics, politics, and even science, which all of them have been depended on the human being. Consequently, certainty and truth became humanistic, that is, man became as the axis of certainty and truth, which the most important result of that is the relativity of certainty and its restriction to human knowledge, will, and ability. This paper tries to discuss the above subjects, considering some of the important thinkers of modern and postmodern philosophy like as Descartes, Kant, Nietzsche, Sartre, and Heidegger. It also attempts to show that although Heidegger complained to subjectivism and modernistic approach of truth, his effort to redefine truth and certainty was not successful and could not rescue it from a crisis. That is because he could not go beyond human understanding to reach a holy and absolute certainty and truth, while – according to this paper – the only real way is paying attention to divine certainty, revelation, and God.
