Besides, they teach us to be confident that we obtain forgiveness of sins because of contrition and love. What else is this than to put confidence in our works, not in God’s Word and promise about Christ? But if the Law is enough for receiving the forgiveness of sins, what need is there of the Gospel? What need is there of Christ if we receive forgiveness of sins because of our own work? [76] We, on the other hand, call consciences away from the Law to the Gospel, and from confidence in their own works to confidence in the promise and Christ. We do so because the Gospel presents Christ to us and freely promises the forgiveness of sins for Christ’s sake. In this promise it asks us to trust, namely, that we are reconciled to the Father for Christ’s sake, not for the sake of our own contrition or love. For there is no other Mediator or Atoning Sacrifice than Christ.
– Apology of the Augsburg Confession, XIIa (V) 75–76
the mountains will depart, the hills will totter, but My steadfast love will not depart from you, and the covenant of My peace will not totter,’ says Yahweh who has compassion on you.” (Is 54:10)