Rom 1:2-4, 1 Cor 15:1-4, 2 Tim 3:15

In the Old Testament, the psalmist confessed that what God had done was communicated to the descendants of the Israelites so that they could believe in God. (Psalms 78:2-8)

Psalms 78:2 I will open my mouth in a parable: I will utter dark sayings of old: 3 Which we have heard and known, and our fathers have told us. 4 We will not hide them from their children, shewing to the generation to come the praises of the Lord, and his strength, and his wonderful works that he hath done. 5 For he established a testimony in Jacob, and appointed a law in Israel, which he commanded our fathers, that they should make them known to their children: 6 That the generation to come might know them, even the children which should be born; who should arise and declare them to their children: 7 That they might set their hope in God, and not forget the works of God, but keep his commandments: 8 And might not be as their fathers, a stubborn and rebellious generation; a generation that set not their heart aright, and whose spirit was not stedfast with God.

The coming of the Son of God, promised through the prophets in the Old Testament, was fulfilled. Jesus is the Son of God, the Christ, who came as a descendant of David and was resurrected three days after he died. (Romans 1:2-4)

Romans 1:2 (Which he had promised afore by his prophets in the holy scriptures,) 3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh; 4 And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:

The gospel that Jesus is the Christ has been preached to us. (1 Corinthians 15:1-4; 2 Timothy 3:15)

1 Corinthians 15:1 Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; 2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. 3 For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; 4 And that he was buried, and that he rose again the third day according to the scriptures:

2 Timothy 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.