Charles Spurgeon Commentary Matthew 19:17

"And he said unto him, Why askest thou me concerning that which is good? One there is who is good: but if thou wouldest enter into life, keep the commandments." — Matthew 19:17 (ASV)

Our Lord did not care for empty compliments, and so He asks, Why callest thou me good? Many modern heretics praise Jesus, and their commendations are such an insult to His glorious person that He might well say, Why callest thou Me good? Did this man really mean it? If so, the Lord Jesus would let him know by a hint that He to whom he spoke was more than man. The argument is clear—either Jesus was good or he should not have called Him good, but as there is none good but God, Jesus, who is good, must be God.

As for the question of having eternal life through a good work, Jesus answers him on his own ground. Life by the law comes only by keeping its commands: If thou wilt enter into life, keep the commandments. No one has ever fulfilled them so as to be good. Did this young man think that he could do so? Yet, on the ground of law, if he would deserve eternal life as a reward, he must be as good as God and keep the commandments to perfection. Thus the rugged way of works was set before him, not that he might attempt to win eternal life by that means, but that he might perceive his own shortcomings and so feel his weakness as to look for salvation by some other method.