Having established that Jesus is the Christ, Peter calls on the crowd to repent. At its most basic level, repentance involves turning from sin and submitting to Christ as King. In Acts 3:22–23 we are told that our response to Jesus determines whether or not you belong to God’s people.
In Acts 3:25 Peter reminds his audience that even if they have the privilege of knowing God’s promises (he even calls them the sons of the prophets
), the mentioned blessing to Abraham will come only to those who turn from their wickedness and submit to God’s servant. This is a call to publicly identify with Jesus and his church, to be baptized in his name as we see also in Acts 2:37–41.
In light of this call I think there is some specific application to those of us who have grown up in and around the church. If you were baptized as an infant, if you know the promises of God, and if you gather with his people, there is a sense in which you are already identified with Jesus and his body, the church. There is, however, still something lacking if you have not made a public profession of your faith. It is necessary for all believers to publicly declare that they believe the promises of the gospel, take on their responsibilities in God’s church, and participate in the Lord’s Table.
Public confession is a key part of identifying with Christ and his people. The apostle Paul writing in Romans 10:9 famously says “If you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.” When he talks of a confession there, he references the public confession that adult believers would make with their baptism when they join the church. All children growing up in the covenant and the church should come to this profession of faith.
22 Moses said, ‘The Lord God will raise up for you a prophet like me from your brothers. You shall listen to him in whatever he tells you.