Jesus' tough answer of "sell whatsoever thou hast, and give to the poor" was not intended to hurt this young man. It was said from a heart of love and intended for his own good. This man's money had become his god and it had to be dethroned before Jesus could become Lord.
The one thing this young man lacked was faith in Jesus as his Savior. He was trusting in his goodness and not in the salvation that Jesus offered as a gift. Millions of people are making the same mistake. They trust in themselves instead of God.
Jesus only came to save sinners. Unless an individual acknowledges that he is a sinner, he cannot be saved. Because the whole world is guilty before God, He has provided one way of salvation for everyone. In the same way that everyone is guilty, everyone also has been justified freely by God's grace.
That doesn't mean everyone is saved. Everyone has had the sacrificial offering of Jesus made for their sins by grace but grace alone doesn't save.
We have to put faith in what God has provided for us by grace. Although the price has been paid for the sins of the whole world, only those who receive it by faith will benefit from the salvation that Jesus offers.