What is reason? Reason is the consciousness of the ontological tendency that is the human person toward the Absolute. The person, made in the image of the Divine Persons, is yearning for a vision of Absolute Being. The appearance of the Second Person of the Trinity as gift to be known is offered to this tendency, and if the person says “Yes,” Revelation takes place. The veil is removed. Reason achieves Truth as Absolute.
Reason needs faith to behold the being of the person transfigured as act by going out of self. Without the experience of going out of self, reason has wilted under the weight of empirical facts of more and less.
To the question: Is faith a gift of God? In this explanation of faith as gift of self by the one who receives the Word, it seems that it is the believer’s act, and not a divine gift.
Answer: Faith is a gift of God in that the Word of God that is given is the Person of the Son as gift. But also, it is impossible to make the gift of self to receive the Word without being loved first. We do not seek God first. He seeks us, and gives Himself to us. Christianity is the only religion that is gift and consists in response, not search.
Revelation does not come to us like meteor that drops into our minds. It is the self who freely receives Christ by prayer, experiences Him, and is able to say as Simon-become-Peter: “You are the Christ, the Son of the living God” (Mt. 16,16).
But even deeper. I do not have a self to give if I have not been loved first. Since we have been created in the image of the Son Who receives all that He is from the Father and His very existence is reception, so also, we must receive the love (grace) of God that gives us our name and identity so that we can master ourselves, get possession of ourselves to as to make the gift of receiving the Word. We cannot believe without God, but God does not believe for us. It is our act and our freedom. And I insist in the light of Dei Verbum #5, that faith is not the mere reception of supernatural ideas but the gift of reception of the very Person of the Son Who is the revelation of the Father. The revelation we receive is the Son Himself. See the Ratzinger handout from “Principles of Catholic Theology” Ignatius (1985) 79-81.