I agree that the young man he fail, but the law never fail. Let's go back into Matthew 19: 16 And, behold, one came and said unto him, Good Master, what good thing shall I do, that I may have eternal life? 17 And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments. This is not the schoolmaster law, this is the Ten Commandment (Royal law). The schoolmaster law was the animal sacrificial law, let's go to Galatian 3: (v.19) Wherefore then serveth the law? A question is being asked here. Then why should we serve this law? It was added because of transgression, till the seed should come to whom the promise was made; the law that we are talking about here was added because of sin. But we now know that sin is the transgression of the law. The transgression of the law (commandments). Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law. Now we have just read the biblical definition of sin, the transgression (breaking) of the law (commandments.)
How do you add a law if sin is the transgression of the law? Because there are two sets of laws, you have God’s holy commandments which abided forever, and you had the animal sacrificial law which was added because of sin, but it was only good until the seed should come to whom the promise was made, and that seed was Jesus.
(v.24) Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. This animal sacrificial law was only a schoolmaster.
And this schoolmaster taught you that when you sinned in ignorance blood had to be shed (an animal sacrificed). But Christ being the ultimate sacrifice shed his precious blood once and for all, and by doing this putting an end to the animal sacrificial law.
So Let's go back to Matthew 19: 18 He saith unto him, Which? Jesus said, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness, 19 Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself. 20 The young man saith unto him, All these things have I kept from my youth up: what lack I yet?
Now the young should have never tried to justify his position, because if you keeping these Commandments as Jesus says that all you needed to do enter in to life. But because the young man said what lack I yet, Jesus let the young man know that there is another step, because the young man took the situation there.
Let's prove this in Psalm 19: 7 The law of the LORD is perfect, converting the soul: The testimony of the LORD is sure, making wise the simple. 8 The statutes of the LORD are right, rejoicing the heart: The commandment of the LORD is pure, enlightening the eyes. 9 The fear of the LORD is clean, enduring for ever: The judgments of the LORD are true and righteous altogether.
Notice, that the law of the Lord is perfect and converting the soul. The commandment of the LORD is pure, enlightening the eyes
That's one reason the young man was bless and had great possession because he kept the law from his youth up.