Catechism of the Catholic Church
To believe in Jesus Christ, the Son of God
151 For a Christian, believing in God cannot be separated from believing in the One he sent, his "beloved Son", in whom the Father is "well pleased"; God tells us to listen to him. 18 The Lord himself said to his disciples: "Believe in God, believe also in me." 19 We can believe in Jesus Christ because he is himself God, the Word made flesh: "No one has ever seen God; the only Son, who is in the bosom of the Father, he has made him known." 20 Because he "has seen the Father", Jesus Christ is the only one who knows him and can reveal him. 21
Notes:
18 Mk 1:11; cf. 9:7
19 Jn 14:1.
20 Jn 1:18.
21 Jn 6:46; cf. Mt 11:27.
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.