That isn't class envy. That is acknowledging that humans who spent a lot of time trying to accumulate weath and stuff may tend to be more focused on the material rather than the spiritual.Read Jesus' earlier admonition that the questioner give away all his possessions to the poor.
Just prior to this 'RULER' coming to Jesus, Jesus had called his disciples unto Him..Luke 18:16 "Suffer little children to come unto ME, and forbid them NOT: for of such is the kingdom of God.
Luke 16:17 Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child shall in no wise enter therein."
verse 18 And a certain *RULER* (not just an everyday, run of the mill questioner) asked Him, saying "Good Master, what shall I do to inherit eternal life?'
verse 19 And Jesus said unto him, "Why callest thou ME good? none is good, save one, that is, GOD.
Matthew 19:17 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."
Luke 18:20 Thou knowest the commandments, Do not commit adultery, Do not kill, Do not steal, Do not bear false witness, Honour thy father and thy mother."
Notice that Christ did NOT quote the first five to this guy, and that is what he was meaning when He told this 'rich' man verse 22 "Yet lackest thou one thing: sell all that thou hast, and distribute unto the poor, and thou shalt have treasure in heaven: and come, follow ME."
See this man's riches was his 'god' and what he spent all his time focusing upon. He did not have time to follow the first five commandments.