Peter explained "'that God had sworn to [David] with an oath to seat one of his descendants on his throne'" (Ac 2:30). "'He was a prophet'" (:30) and predicted "For You will not abandon my soul to Sheol; nor will You allow Your Holy One to undergo decay" (Ps 16:10). "Surely the Lord God does nothing unless He reveals His secret counsel to His servants the prophets" (Am 3:7). Peter said that David "'looked ahead and spoke of the resurrection of the Christ'" (Ac 2:31). "'This Jesus God raised up again, to which we are all witnesses'" (:32). He also said that Jesus was "'delivered over by the predetermined plan and foreknowledge of God'" (:23). God's plan is cited by Matthew (Mt 1:22-23) when he quotes the prophecy "the Lord Himself will give you a sign: Behold, a virgin will be with child and bear a son, and she will call His name Immanuel'" (Isa 7:14). Matthew also speaks of the prophecy regarding the Messiah being born in Bethlehem (Mt 2:6) quoting "'from you One will go forth for Me to be ruler in Israel. His goings forth are from long ago, from the days of eternity'" (Mic 5:2).
At Corinth Paul began "solemnly testifying to the Jews that Jesus was the Christ" (Ac 18:5). The angel had said "there has been born for you a Savior, who is Christ the Lord" (Lk 2:11). He was "born for you." Mary was told "'you shall call His name Jesus, for He will save His people from their sins'" (Mt 1:21). Scripture says Jesus is Lord. Jesus confessed, "'You call Me Teacher and Lord; and you are right, for so I am'" (Jn 13:13). Peter stated "that God has made Him both Lord and Christ'" (Ac 2:36). "Every tongue will confess that Jesus Christ is Lord" (Php 2:11). When a person is referred to as a "lord" it means he occupies a supreme place.
When Peter explains Jesus' position he shows "'having been exalted to the right hand of God . . . [he] received from the Father the promise of the Holy Spirit'" (Ac 2:33). Being exalted would be occupying a "supreme place" and he can be referred to as "Lord." To prove it Peter explains that from Jesus' position "'He has poured forth this which you both see and hear'" (:33). This is substantiated because he quotes "'It will come about after this that I will pour out My Spirit on all mankind'" (Joe 2:28). Even Jesus refers to prophecy to make a point. He asks the Pharisees, "'How does David in the Spirit call Him 'Lord,''"(Mt 22:43) for "'if David then calls Him 'Lord,' how is He his son?'" (:45). The reference is "The Lord says to my Lord: 'Sit at My right hand until I make Your enemies a footstool for Your feet'" (Ps 110:1). Jesus was proving that he was the Messiah and "no one was able to answer Him a word" (Mt 22:46).