Mark 10:21 Then Jesus beholding him loved him, and said unto him, One thing thou lackest: 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.

While many mistake this verse to mean that God wants believers to have lack, that is not true (Ephesians 3:20, Matthew 6:33, Genesis 12:2). God knows our hearts and desires that we obey Him and put nothing and no one else before Him. The young ruler loved his possessions more than He loved God and was unwilling to submit all of Himself to God. What area are you withholding from God? Surrender all and trust Him.