This is the true gospel.
God requires two things of us: punishment for our sins and perfection in our lives. Our sins must be punished, and our lives must be righteous. But we cannot bear our own punishment, and we cannot provide our own righteousness. Therefore, God, out of His immeasurable love for us, provided his own Son to do both. Christ bears our punishment, and Christ performs our righteousness. And When we receive Christ, all of his punishment and all of his righteousness is counted as ours.
—John Piper
This Momentary Marriage
Via: Of First Importance