According to St. Augustine Faith and Reason are intertwined, overlapping each other, but without excluding each other. In this way the faith is perme­ated by the intellect and it is founded on the authority of the reason, that is essential for in-depth „knowledge”. On the other hand, „knowledge” – rea­son is irreplaceable to „believe”. In such a context two very characteristic of our author’s statements can be seen: Crede ut intelligas, and intellige ut credas! The call of the blessed of Hippo: Intellectum valde ama! can also be included in it. It is a meaningful fact that there is not known a single case in which the Augustinism would split up the reason with the faith. An absolute Christocentrism of Augustine is present in the background of the discussion about the faith and the reason: speculation is not a goal in itself, but it only serves to get closer to the mystery of God and the mystery of a man in Christ. The reason and the faith (the authority) are two factors of getting to know the truth. One can speak of a kind of gnoseological dualism. The faith is the ac­ceptance of the truth because of the authority of the witness. Knowledge leads to the possible conclusions and the faith gives certainty and consistency.