In religion our only hope is to live a life good enough to require God to bless us, so every instance of sin and repentance is therefore traumatic, unnatural, and threatening. Only under great duress do religious people admit they have sinned, because their only hope is their moral goodness.
In the gospel the knowledge of our acceptance in Christ makes it easier to admit that we are flawed, because we know we won’t be cast off if we confess the true depths of our sinfulness. Our hope is in Christ’s righteousness, not our own, so it is not as traumatic to admit our weaknesses and lapses.
Whereas in religion we repent as little as possible, the more we feel accepted and loved in the gospel, the more and more often we will be repenting. Although there is some bitterness in any repentance, in the gospel there is ultimately a sweetness. This creates a thoroughly new dynamic for personal growth. The more we see our own flaws and sins, the more precious, electrifying, and amazing God’s grace appears to us. On the other hand, the more aware we are of God’s grace and our acceptance in Christ, the more able we are to drop our denials and self-defenses and admit the true dimensions of our sin.
Tim Keller, Gospel in Life, 28-29