M. Schmaus on Believing in Jesus

"Although the original substance of the words and actions of Jesus can thus be attained through the apostolic formulations, it is faith alone that opens up the understanding of Christ.  If the New Testament witness to Christ consists in accounts that are not so much historical as kerygmatic, and hence witnesses of faith, then the appropriate response to them is our own faith in return.  This likewise follows from the content itself which is proclaimed, since it is nothing other than the risen Christ, living and present.  But Christ cannot be affirmed as an object: he always remains subject.  Hence proclamation can aim only at personal encounter with Jesus Christ.  This takes place in faith; faith is the surrender of the believing I to the Thou of Jesus Christ.  If even ordinary encounter between persons requires faith as a preliminary, this is true of the encounter with the glorified Lord in a special and unique way.  For in the resurrection he has entered into the mystery of God, and so, in being proclaimed, he speaks out of the mystery of God.  The one who hears through this proclamation is called into the mystery of God.  The way of rational knowledge does not lead to this encounter, but only the way of decision, in which man submits himself to the divine mystery.  Because the historical words and actions of Jesus are most intimately related to the life of the Risen One, their true sense can be grasped only in faith; indeed they are in their totality nothing other than forms of expression of the one Jesus Christ.  Faith, in the form of a personal encounter,  naturally includes the acceptance of Jesus' words and teachings (assent to revealed truth); this, however, is only one element within the total event of faith.  

"In the last analysis, man is capable of decision for Jesus only when he is empowered to make it by Jesus himself. In the call, of which man becomes aware through the gospel proclamation, Christ so acts upon the genuine hearer that his hearing of the call through the words of men becomes at the same time a  following of it; that is, faith is at once both grace and a human decision."

Michael Schmaus, Dogma 3:  God and His Christ