6 Through divine revelation, God chose to show forth and communicate Himself and the eternal decisions of His will regarding the salvation of men. That is to say, He chose to share with them those divine treasures which totally transcend the understanding of the human mind. As a sacred synod has affirmed, God, the beginning and end of all things, can be known with certainty from created reality by the light of human reason (see Rom. 1:20); but teaches that it is through His revelation that those religious truths which are by their nature accessible to human reason can be known by all men with ease, with solid certitude and with no trace of error, even in this present state of the human race.
Source: Dei Verbum (Vatican.va)