This passage (Matt 19:16-22) was erroneously interpreted by some of the ancients, whom the Papists have followed, as if Christ taught that, by keeping the law, we may merit eternal life. On the contrary, Christ did not take into consideration what men can do, but replied to the question, What is the righteousness of works? or, What does the Law require? And certainly we ought to believe that God comprehended in his law the way of living holily and righteously, in which righteousness is included; for not without reason did Moses make this statement,
We have no right, therefore, to deny that the keeping of the law is righteousness, by which any man who kept the law perfectly--if there were such a man--would obtain life for himself. But as we are all destitute of the glory of God, (Romans 3:23,) nothing but cursing will be found in the law; and nothing remains for us but to betake ourselves to the undeserved gift of righteousness. And therefore Paul lays down a twofold righteousness, the righteousness of the law, (Romans 10:5,) and the righteousness of faith, (Romans 10:6.) He makes the first to consist in works, and the second, in the free grace of Christ.
- I call heaven and earth to witness that l have this day showed you life, (Deuteronomy 30:19.)
Hence we infer, that this reply of Christ is legal, because it was proper that the young man who inquired about the righteousness of works should first be taught that no man is accounted righteous before God unless he has fulfilled the law, (which is impossible,) that, convinced of his weakness, he might betake himself to the assistance of faith. I acknowledge, therefore, that, as God has promised the reward of eternal life to those who keep his law, we ought to hold by this way, if the weakness of our flesh did not prevent; but Scripture teaches us, that it is through our own fault that it becomes necessary for us to receive as a gift what we cannot obtain by works.
If it be objected, that it is in vain to hold out to us the righteousness which is in the law, (Romans 10:5,) which no man will ever be able to reach, I reply, since it is the first part of instruction, by which we are led to the righteousness which is obtained by prayer, it is far from being superfluous; and, therefore, when Paul says, that the doers of the law are justified, (Romans 2:13,) he excludes all from the righteousness of the law.John Calvin, Commentary on Matthew