Commentaries:
Christ links repentance with the Kingdom of God and believing the gospel. Once one hears the true gospel and believes it, he begins to change the way he thinks. Peter ties repentance with forgiveness of past sins and God's giving of His Spirit. Once the Ethiopian eunuch heard Philip's explanation of the Bible, he changed his thinking (repented) and was baptized. Initial repentance includes recognition, acceptance, and belief of the true gospel and making changes in one's life to conform to the new way.
Martin G. Collins
Basic Doctrines: Repentance