15 "Abraham rejoiced that he would see my day; he saw it and was glad" ( Jn 8:56). According to these words of Jesus, Abraham’s faith pointed to him; in some sense it foresaw his mystery. So Saint Augustine understood it when he stated that the patriarchs were saved by faith, not faith in Christ who had come but in Christ who was yet to come, a faith pressing towards the future of Jesus. Christian faith is centred on Christ; it is the confession that Jesus is Lord and that God has raised him from the dead (cf. Rom 10:9). All the threads of the Old Testament converge on Christ; he becomes the definitive "Yes" to all the promises, the ultimate basis of our "Amen" to God (cf. 2 Cor 1:20). The history of Jesus is the complete manifestation of God’s reliability. If Israel continued to recall God’s great acts of love, which formed the core of its confession of faith and broadened its gaze in faith, the life of Jesus now appears as the locus of God’s definitive intervention, the supreme manifestation of his love for us. The word which God speaks to us in Jesus is not simply one word among many, but his eternal Word (cf. Heb 1:1-2). God can give no greater guarantee of his love, as Saint Paul reminds us (cf. Rom 8:31-39). Christian faith is thus faith in a perfect love, in its decisive power, in its ability to transform the world and to unfold its history. "We know and believe the love that God has for us" ( 1 Jn 4:16). In the love of God revealed in Jesus, faith perceives the foundation on which all reality and its final destiny rest.
Source: Lumen Fidei (Vatican.va)