In general, revelation and faith intertwined together. They can't be separated. According to Avery Dulles, SJ, "faith is assent and the acceptance of a revealed message on the word of the divine revealer." In the document Dei Verbum, "By faith, man freely commits his entire self to God, making the full submission of his intellect and will to God who reveals and willingly assenting to the Revelation given by Him."
It should be clarified that God's revelation in some aspect is also pertaining to the doctrine or words of God(Gospel). On the other hand, faith in some aspect pertains to belief or believing.
Revelation is the object of faith. Even though, human reason is capable of knowing the existence of a personal God, it is not enough for man to be able to enter a real intimacy with God. Entering a real intimacy with God is by believing His revelation and His masterplan of salvation which are hidden in mystery. But how could we enter a real intimacy with God if His revelation and masterplan of salvation are hidden in mystery? ...By having faith. Faith is above human reason. "...faith is the substance of things hoped for, the evidence of things not seen"(Hebrews 11:1). That's why we will not know and reach the truth of the revelation of God if we don't possess faith. Faith should be our response to God's revelation. Do you know how is it very essential to us to have faith in God's revelation?
Faith in God's revelation(Gospel) leads to salvation. St. Paul told us that the Gospel is the power of God to salvation for everyone who believes(Romans 1:16). Our Lord Jesus Christ Himself required us to believe or to have faith in the Gospel in order to be saved:
"Go into the world and preach the Gospel to every creature.
He who believes and is baptized shall be saved, but he who does not believe shall be condemned."
Thus, it would be futile even if man will be baptized but doesn't believe in the Gospel (God's revelation), for he will not be saved. Instead, he will be condemned.