A classic hymn prays: “O holy, blessed Trinity, / Divine, eternal Unity, / O Father, Son, and Holy Ghost, / This day your name be uppermost. . . . / My Maker, hold me in your hand; / O Christ, forgiven let me stand; / Blest Comforter, do not depart, / With faith and love enrich my heart.”
All three Persons of the Trinity play their role in the believer’s salvation and daily spiritual life. On the day of Pentecost, Peter declared God’s eternal plan of redemption, including the involvement of the entire Trinity (vv. 30–36). Jesus, the Son, was the man they had recently seen arrested and crucified. He was in fact God’s promised Messiah, from the line of David but greater than the famous king—as David had prophetically known would be the case. Now resurrected, Jesus had been exalted to the right hand of God, having completed His mission of salvation.
The Father was the maker and fulfiller of the Davidic covenant, the One responsible for the overall plan, including the sending of His own Son. He was the One sovereignly calling Peter’s listeners to repentance and faith in Christ. Finally, the third Person of the Trinity, the Holy Spirit, was the explanation for the phenomenon of tongues they had just witnessed, in which everyone had heard the gospel proclaimed in their own language (2:1– 12). He had been sent by the Father and the Son as part of the gift of salvation, to enable and empower the newborn church to spread the good news of God’s love far and wide.
In response, thousands of Peter’s listeners were “cut to the heart,” repented, believed on Jesus, and were baptized the same day (vv. 37–41).