Acts 2:38 (ESV)

38 And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit.

Acts 2:38 describes union with Christ or incorporation into the body of Christ in terms of its basic benefits: the remission of sins (justification) and the gift of the Spirit (new life) appropriated by repentance (faith) and sealed by (water) baptism.1