When a rich young ruler asks Jesus, “What shall I do to inherit eternal life?”, Jesus answers very simply: “Keep the commandments.” (Mt 19:16-17) Is this unexpected? Why would Jesus answer this way if salvation is by faith alone, not by works? (Ro 3:28)
Since the young man seems to imply he can earn his way to heaven (“What shall I do?”), perhaps Jesus is merely answering his question directly. But the fact the young man is seeking eternal life implies he suspects there might be a problem, either a sin of commission or one of omission. (Ja 4:17)
In any case, the young man remains unsatisfied and asks Jesus which commands he needs to keep. Jesus picks out a few, including the classic, Love Your Neighbor as Yourself (Mt 19:18-19) — enough to awaken in this young soul his need for a new heart, if he’s been paying attention. (Ga 6:15)
Yet the young man persists, evidently ignorant of his true need, thinking he’s kept the high standard of God‘s law, still uncertain of his destiny. So, Jesus offers further revelation; to have eternal life he must surrender completely to Jesus Christ and rely entirely upon Him in faith. Keeping the commandments is necessary for salvation but insufficient; one must receive Jesus Christ as Savior as well as Lord and Master. The requirement is to give up everything, including himself; forsake all and follow Him. (Lk 14:26)
Evidently, this final observation is entirely consistent with Christ’s first reply; it is not contradictory but provides additional insight: keeping God’s commandments is a necessary condition for having eternal life but not a sufficient one. Willingness to obey God is required because willful disobedience is rebellion against the King — the opposite of trusting submission and faith. While it is true no child of God can keep Torah perfectly or earn their way in, it is also true that those who continue break Torah willfully as a pattern of life are not God’s children. (1Jn 3:9)
At this final step, the young man finally understands and is very sorrowful. He wanted eternal life as an added bonus while living his best life now, but he was unwilling to give up the pleasures of his temporal life to gain an eternal one. And Jesus observes that this prevents any soul from entering His kingdom (Mt 19:23); no one enters Heaven who chooses it as an afterthought (Lk 14:33), only those who seek His kingdom as their first, primary, and overriding objective will find it. (Mt 13:45-46) This is indeed what saving faith looks like. (He 11:6)