What does Acts 2:27 mean?
Peter is using David's conversation with God about Jesus to show a crowd in Jerusalem that Jesus is the Messiah. In Psalm 16:8–11, David identifies his Lord as the one who grants him strength and authority (Psalm 16:8) and does not experience permanent death (Psalm 16:10).Acts 2:27 is the core of the quote and the center of the chiasm. Jesus was resurrected from the dead. Because of that, we also have a hope and a path to eternal life (Acts 2:26, 28). Jesus' life and presence bring us joy (Acts 2:25–26, 28). As Paul later proves in 1 Corinthians 15:12–19, the resurrection of Christ is the root of all good things.
We know that David's psalm is addressed to God in part because the first line starts, "Preserve me, O God…" (Psalm 16:1). But also, God is the one who decides who goes to and stays in Hades. The Old Testament doesn't present a fully developed theology of heaven and hell. Those ideas were more fully explained in the New Testament. "Hades" is Greek for the Hebrew Sheol which is just a term for where the souls of the dead go.
In most of Psalm 16, David spoke for himself. In Psalm 16:10, he spoke for the "Holy One." Peter explains that David spoke for one of his descendants, the Jewish Messiah, who David foresaw would be raised from death (Acts 2:30–31).
"Corruption" is from the Greek root word diaphthora and means the decay experienced by a dead body. In direct contrast, Jesus shed His original body and gained a new, imperishable body. But "corruption" also refers to the pit or grave. Jesus did not stay in the grave as David did. Peter's audience knows where David's body lay—the tomb is in Jerusalem (Acts 2:29). But, as there is no body for Jesus, this is strong evidence that Jesus is God's "Holy One" as well as David's "Lord" (Acts 2:25).
Prophecy in the Psalms is often hard to figure out. It's notable that Peter didn't unpack this passage until he had received the Holy Spirit (Acts 2:1–4).
