By the power and blessing of God leave the old life behind, and let him give you a new life. Be changed and believe the gospel. The two go hand-in-hand: repentance and belief are twin sisters. You believe in Christ; you trust in his suffering and death on your behalf to cancel the power and the penalty of sin and take away your condemnation. You yield your life to him. The call for change – ‘Lord, change me; give me a new life.’ That change and the repentance of sin go hand in hand. It would be the signature of the entire ministry of Christ. Mark puts it right at the beginning and that's where it belongs.