What is the wickedness from which Simon must turn?
Acts 8:22 (ESV)
22Repent, therefore, of this wickedness of yours, and pray to the Lord that, if possible, the intent of your heart may be forgiven you.
Simon must change his thinking and desires. He must realize that God is not someone who exists for his benefit. God cannot be manipulated and controlled. The Spirit cannot be bought and sold.
22 Repent, therefore, of this wickedness of yours, and pray to the Lord that, if possible, the intent of your heart may be forgiven you.