Acts 2:38 is a response from Simon about what the audience ought to do regarding the fact they've just realized that God made Jesus both Lord and Christ, and that they crucified Him.
Repentance therefore in
Acts 2:38 is a combination of the following:
- Realizing, believing, and confessing that Jesus is Lord by the will and edict of God
- Realizing, believing, and confessing that Jesus is the Messiah by the will and edict of God
- In light of these two things, realizing, believing, and confessing that you had the by the will and edict of God Lord and Messiah murdered
If and when you realize, believe, and confess these things, you should be baptized in the name of the Lord Jesus so your sin (crucifying the One God made Lord and Christ) may be forgiven.