The Catechism in Questions & Answers

10. What do we understand by the idea of faith as a response to God’s revelations?

Faith is indispensable in order to come into the proximity of God, but faith is not something that human beings can bring about on their own. Faith is an act of God’s grace upon a human being, in other words, a gift Human beings are to have a longing for this gif and are to accept it. Faith leads human beings to recognise God, trust in God, and lead a life in accordance with the will of God.
 

Faith: see Question 239. et seq.

“Now faith is the substance of things hoped for, the evidence of things not seen.”
Hebrews 11: 1
 

“But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him.”
Hebrews 11: 6