What good thing shall I do, that I may have eternal life?

This ruler had a high estimate of his own righteousness. He did not really suppose that he was defective in anything, yet he was not altogether satisfied. He felt the want of something that he did not possess. Could not Jesus bless him as He blessed the little children, and satisfy his soul want?
In reply to this question Jesus told him that obedience to the commandments of God was necessary if he would obtain eternal life; and He quoted several of the commandments which show man’s duty to his fellow men. The ruler’s answer was positive: “All these things have I kept from my youth up: what lack I yet?”
Christ looked into the face of the young man, as if reading his life and searching his character. He loved him, and He hungered to give him that peace and grace and joy which would materially change his character. “One thing thou lackest,” He said; “go thy way, sell whatsoever thou hast, and give to the poor, and thou shalt have treasure in heaven: and come, take up the cross, and follow Me.”
Taken from the book "A Call to Stand Apart" page. 14