Jesus came to reveal God, the true “face” of God. This knowledge is more than head knowledge but direct and intimate knowledge: knowing Him. Faith is the object of this knowledge and this knowledge is the object of faith; both grow together. But most importantly, love grows with this knowledge because to know God is to love Him; He’s that good; He’s the very source of goodness.
At the Fall, “They become afraid of the God of whom they have conceived a distorted image - that of a God jealous of his prerogatives”, as the catechism teaches. That fear and distorted image persists in us; we’re born with it; it’s part of our separation or exile from God and the lack of knowing Him that we’re all born with. The New Covenant, as the time became ripe in human history, is the antidote:
No longer will they teach their neighbor,
or say to one another, ‘Know the Lord,’
because they will all know me,
from the least of them to the greatest,”
declares the Lord. Jer 31:34
So Jesus came to give us the knowledge that Adam dismissed and spurned at the time, which could’ve been his, growing on the greater knowledge that he already possessed. He hadn’t yet come to appreciate God’s definitive supremacy and of his own complete dependency on Him. Pride had entered the human scene-and that pride actually opposes the “knowledge of God”:
398 In that sin man preferred himself to God and by that very act scorned him. He chose himself over and against God, against the requirements of his creaturely status and therefore against his own good.
The Cross shows the extent to which God is willing to go to prove how deeply He loves us, Perfect Innocence suffering an excruciatingly humiliating and painful death in human flesh at the hands of His own creation-in spite of our sin, forgiving all the while. “They hated me without reason”, Jesus reveals about his persecutors, quoting Psalms. Anyway:
"Now this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent." John 17:3