“[Repentance] is perpetual. . . . The Christian is a new person in Christ, but he is imperfectly renewed. He has died to sin and has been raised to new life. But this mortification and vivification continue throughout the whole course of his life on earth. We are no longer what we once were, but we are not yet what God calls us to become; and as long as that is the case we are called to an ongoing battle for holiness.
[ . . .] Repentance does not merely begin the Christian life. According to Scripture, the Christian life is repentance from beginning to end! So long as the believer is simul justus et peccator (at the same time righteous and yet a sinner), it can be no other way.
[ . . .] True repentance can never be reduced to a single act only found at the beginning of the Christian life. It arises in the context of our union with Jesus Christ; and since its goal is our restoration into the image of Christ, it involves the ongoing practical outworking of our union with Christ in his death and resurrection–what Calvin calls mortification and vivification–that is, being conformed to Christ crucified and risen.”
– Sinclair Ferguson, The Grace of Repentance, 20, 28, 30.