But the doers of the law shall be justified.’ Yes, this is so if a person has kept the law, but first show me such a man. In the same Epistle to the Romans, Paul later declares that God’s promise of eternal life to all who keep his law is of no value to us because we can never perform it adequately (Rom. 8:3). In fact, by nature we are completely hostile to God’s righteous standards. Now that he has regenerated us by his Holy Spirit, we are entirely indebted to him; every good thing we possess we have received from his hand, and he simply rewards his own gifts in us. Can we, therefore, speak of merit? No. Indeed, we must go further and say that even though our Lord deigns to crown our works when they are good in his sight, they can only be partly good, for there will always be enough sin mixed in with them to condemn us. Thus, we are stripped of all confidence in our own righteousness, because our works have insufficient worth in the eyes of God. If we were being judged by the text, ‘The man that doeth them shall live in them’, our works would be shown to be totally offensive to God. He would say, as it were, ‘You are all dead, damned and lost. Why? Because none of you have done the things I asked you to do, whereas it was your duty to do so.’

~ John Calvin