In the Pentecost speech, Peter does not yet develop an elaborate doctrine of redemption as Paul would later do in his epistles, but all the essential elements are already present. His message is centered on the person of Jesus, his death, his resurrection and the forgiveness of sins granted in his name.
1- The death of Jesus is part of God's plan
Peter affirms that the crucifixion is not an accident of history:
“This man, delivered up by the determinate counsel and foreknowledge of God, you have crucified” (Acts 2.23).
Thus, the death of the Messiah is part of God's redemptive purpose. Human responsibility is real, but it is exercised within the framework of the divine plan, already announced by the prophets (Isaiah 53.4-6; Isaiah 53.10).
2- The resurrection confirms the value of his sacrifice
Peter then proclaims:
“God raised him up” (Acts 2.24).
The resurrection appears as the proof that God accepted the work of the Messiah. It is the divine answer to the condemnation pronounced by men (Romans 4.25).
3- The exalted Jesus is now Lord and Messiah
The climax of the speech is reached when Peter declares:
“Therefore let all the house of Israel know assuredly that God has made this Jesus, whom you crucified, both Lord and Christ” (Acts 2.36).
The one who was rejected and put to death is now recognized as the exalted Lord. Redemption is therefore tied to his person.
4- Forgiveness of sins is obtained in his name
When the crowd asks:
“Brethren, what shall we do?” (Acts 2.37),
Peter answers:
“Repent, and let every one of you be baptized in the name of Jesus Christ for the forgiveness of your sins” (Acts 2.38).
This declaration is crucial. Forgiveness is no longer associated with the repeated sacrifices of the Temple (Leviticus 4.20), but with the person of the Lord Jesus. Peter implicitly affirms that the work accomplished by the Messiah is sufficient to obtain the remission of sins.
5- The speech already contains the foundations of the Christian doctrine of salvation
Even though the terms “atonement,” “justification” or “reconciliation” are not yet used, Peter already proclaims:
- the death of the Messiah (Acts 2.23);
- his resurrection (Acts 2.24);
- his exaltation (Acts 2.33-36);
- the forgiveness of sins in his name (Acts 2.38);
- the gift of the Holy Spirit (Acts 2.38-39).
Paul's later theological developments will only spell out these fundamental truths more fully (Romans 3.24-26; 1 Corinthians 15.1-4; Ephesians 1.7).
We could thus summarize Peter's thought:
Through his death willed by God, his resurrection and his exaltation, Jesus has become the source of the forgiveness of sins and of salvation. From now on, redemption is no longer sought in the sacrifices of the Temple, but in faith in the Lord Jesus Christ and in his unique sacrifice, whose saving value is attested by his resurrection and his exaltation at the right hand of God.
Thus, from Pentecost on, Peter lays the foundations of the Christian theology of redemption, which will be developed in more detail in the rest of the New Testament.