From today's Advent devotional,
Christ bore our sins in his own body when he died. He took our judgment. He canceled our guilt. And that means the sins are gone. They do not remain in God’s mind as a basis for condemnation. In that sense, he “forgets” them. They are consumed in the death of Christ.
Which means that God is now free, in his justice, to lavish us with the new covenant. He gives us Christ, the greatest Reality in the universe, for our enjoyment. And he writes his own will—his own heart—on our hearts so that we can love Christ and trust Christ and follow Christ from the inside out, with freedom and joy.
And what Freedom and Joy it is!