CCC 422 ‘But when the time had fully come, God sent forth his Son, born of a woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons.’1 This is ‘the gospel of Jesus Christ, the Son of God’:’2 God has visited his people. He has fulfilled the promise he made to Abraham and his descendants. He acted far beyond all expectation – he has sent his own ‘beloved Son’.3

CCC 515 The Gospels were written by men who were among the first to have the faith4 and wanted to share it with others. Having known in faith who Jesus is, they could see and make others see the traces of his mystery in all his earthly life. From the swaddling clothes of his birth to the vinegar of his Passion and the shroud of his Resurrection, everything in Jesus’ life was a sign of his mystery.5 His deeds, miracles and words all revealed that “in him the whole fullness of deity dwells bodily.”6 His humanity appeared as “sacrament”, that is, the sign and instrument, of his divinity and of the salvation he brings: what was visible in his earthly life leads to the invisible mystery of his divine sonship and redemptive mission

1 Gal 4:4-5.
2 Mk 1:1.
3 Mk 1:11; cf. Lk 1:5, 68.
4 Cf. Mk 1:1; Jn 21:24.
5 Cf Lk 2:7; Mt 27: 48; Jn 20:7.
6 Col 2:9.