“You lack one thing: go, sell all that you have and give to the poor, and you will have treasure in heaven; and come, follow me.” (Mark 10:21)
Mark shows us an example of a man who trusted in his wealth rather than in God. The rich young man came to Jesus desiring to know what thing he needed to do to take hold of eternal life. He seemed self-confident, pretty sure of himself, his talents and abilities, his social position, and his wealth. He kept the law, but was not satisfied. Something was missing. Perhaps he had grown weary of doing religious deeds. He wanted to know the one thing that he must do to guarantee salvation.
A lot of people are like that young man. They seek fulfillment, happiness, and satisfaction in material things such as money and possessions or a wide assortment of pleasurable experiences that, as in the case of drugs and alcohol, can be very self-destructive. Or else they seek that satisfaction in helping others so they can be acclaimed as exemplars of morality and altruism. Many even think that such good works earn them a spot in heaven.
But, as Jesus told the rich young man, the way to insure eternal life is to give up his treasures and follow Him, that is to have faith and trust in Him alone. This the young man was not willing to do and so he went away in deep sadness. This does not that mean wealth and possession are wrong in themselves. Using them to define and glorify ourselves, trusting in and depending on them rather than on the one who gives them is. Wealth can become a god we look to meet our needs. Of course anything we make more important or value more than Jesus is a god. Jesus wants us to trust him, to put Him first and He will take care of our needs.