Acts 8:22 commands turn from this great wickedness and pray. Perhaps God will yet forgive your evil thoughts.
What’s interesting about Peter’s comment is that he was speaking to a person who believed Jesus was the Savior and had been baptized to prove it (vs13).
Most Christians would agree that if you believe and have been baptized you are on your way to heaven. Apparently the Apostle Peter held to a different doctrine.
The problem with this new follower of the faith was that he hadn’t really repented from the sin he was committing before he believed and was baptized. The man believed the gospel, he understood its power and sought to become an adherent so took the steps necessary to be part of the community.
The only problem was that he loved power and prestige. He loved these things before he became a Christian and he still loved these things after becoming a Christian. Peter saw this problem revealed by the desire to possess the power of the Holy Spirit and warned this man that he had better get right if he hoped to get home with God.
Repentance involves three parts: admission, confession and separation.
Jesus preached a repentance from sins as part of His gospel. While He invited people to believe in Him He demanded they admit their need for Him, confess Him as the only means to heaven and separate themselves from those things they had been doing that kept them from God.
Baptism is the symbol of repentance; the washing away of the stain of sin and its consequences upon the repentant person, who now confesses with his mouth Jesus is Lord and believes in his heart that God raised Jesus from the dead, which proved God’s acceptance of the Savior’s sacrifice at Calvary.
Unless we separate from our sin we remain in our sin and anyone who remains in sin remains separate from God and His salvation no matter what they confess or in what water they were baptized.
Those who are born again are a new creation, the old has gone and the new has come.
To become a true Christian a person must first repent.