2 For Peter said, “You men of Israel, hear my words; Jesus of Nazareth, a man approved by God among you by powers, and wonders, and signs, which God did by Him in the midst of you, as you yourselves also know: Him, being delivered by the determined counsel and foreknowledge of God, by the hands of wicked men you have slain, affixing [to the cross]: whom God has raised up, having loosed the pains of death; because it was not possible that he should be holden of them.
For David speaks concerning Him, I foresaw the Lord always before my face; for He is on my right hand, lest I should be moved: therefore did my heart rejoice, and my tongue was glad; moreover also, my flesh shall rest in hope: because You will not leave my soul in hell, neither will You give Your Holy One to see corruption.” Then he proceeds to speak confidently to them concerning the patriarch David, that he was dead and buried, and that his sepulchre is with them to this day.
He said, “But since he was a prophet, and knew that God had sworn with an oath to him, that of the fruit of his body one should sit in his throne; foreseeing this, he spoke of the resurrection of Christ, that He was not left in hell, neither did His flesh see corruption. This Jesus,” he said, “has God raised up, of which we all are witnesses: who, being exalted by the right hand of God, receiving from the Father the promise of the Holy Ghost, has shed forth this gift which you now see and hear.
For David has not ascended into the heavens; but he says himself, The Lord said unto my Lord, Sit on My right hand, until I make Your foes Your footstool. Therefore let all the house of Israel know assuredly, that God has made that same Jesus, whom you have crucified, both Lord and Christ.” And when the multitudes exclaimed, “What shall we do then?” Peter says to them, “Repent, and be baptized everyone of you in the name of Jesus for the remission of sins, and you shall receive the gift of the Holy Ghost.” Thus the apostles did not preach another God, or another Fulness; nor, that the Christ who suffered and rose again was one, while he who flew off on high was another, and remained impassible; but that there was one and the same God the Father, and Christ Jesus who rose from the dead; and they preached faith in Him, to those who did not believe in the Son of God, and exhorted them out of the prophets, that the Christ whom God promised to send, He sent in Jesus, whom they crucified and God raised up.
Source: Adversus haereses (New Advent)