“Man, through the exertion of his works, endeavours to be righteous before God and the world. In that he does what should be done, he is more interested in himself than in what is to be done. Paul calls that seeking to establish one’s own righteousness (Rom. 10:3; Phil. 3:9). The law forces one to do this. And by forcing that, the law forces man as doer under the law (Rom. 6:14). Man under the law is the man who does what is to be done, not out of himself, and certainly not without interest in himself. He is the one who is chained to himself and is thus the unfree man. In his ultimately infinte interest in himself he is, as Paul can say, under the power of sin (Rom. 3:9). For sin is nothing other than the compulsion toward oneself into which man places himself.
The characteristic thing about Jesus, however, is that he forgives sin with God’s authority and thus breaks the human complusion toward itself. He battles against sin by being merciful to the sinner. He breaks the power of sin by pitying the misery of the sinners who are people chained to themselves because they have chained themselves to themselves.”
Eberhard Jüngel, God as the Mystery of the World (359).