seen the Father’, Jesus Christ is the only one who knows him and can reveal him.2’ To believe in the Holy Spirit 152 One cannot believe in Jesus Christ without sharing in his 243, 683 Spirit. It is the Holy Spirit who reveals to men whoJesus is. For ‘no one can say “Jesus is Lord”, except by the Holy Spirit’,22 who ‘searches everything, even the depths of God... No one comprehends the thoughts of God, except the Spirit of God.’23 Only God knows God completely: we believe in the Holy Spirit because he is God. The Church never ceases to proclaim her faith in one only God: 232 Father, Son and Holy Spirit. III. The Characteristics of Faith Faith is a grace 552 153 When St Peter confessed thatJesus is the Christ, the Son of the living God,Jesus declared to him that this revelation did not come ‘from flesh and blood’, but from ‘my Father who is in heaven’.24 Faith is a gift of God, a supernatural virtue infused by him. ‘Before this 1814 faith can be exercised, man must have the grace of God to move 1996 and assist him; he must have the interior helps of the Holy Spirit, who moves the heart and converts it to God, who opens the eyes 2606 of the mind and “makes it easy for all to accept and believe the truth’’.’25 Faith is a human act 154 Believing is possible only by grace and the interior helps of the Holy Spirit. But it is no less true that believing is an authen— i~~g tically human act. Trusting in God and cleaving to the truths he has revealed is contrary neither to human freedom nor to human reason. Even in human relations it is not contrary to our dignity to believe what other persons tell us about themselves and their intentions, or to trust their promises (for example, when a man and a woman marry) to share a communion of life with one another. If this is so, still less is it contrary to our dignity to ‘yield by faith the full submission of... intellect and will to God who reveals’,26 and to share in an interior communion with him.