Repent and be baptized in the name of Jesus Christ

Acts 2:25-47
Peter used Psalm 16 8:11 to says about the Jesus who he is. Jesus raised from the dead. God has raised this Jesus to life, and we are all witnesses of it.
Exalted to the right hand of God, he has received from the Father the promised Holy Spirit and has poured out what you now see and hear.
God has made this Jesus, whom you crucified, both Lord and Messiah.
What shall we do? 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.
Why?
Jesus is the Lord and Messiah, Peter said to the crowd and scripture to prove it. And peter and other followers are witnesses of it. So it impress the crowd, 3000 people added their group.
Tell them, witness of it, repent and be baptized in the name of Jesus Christ, then you will receive the gift of the Holy Spirit.
Peter received the Holy Spirit so his life changed and be the witness of Jesus Christ.
How?
In the name of Jesus Christ repent and be baptized is the way of save and peace.