Mark 10:21 (NKJV) 21 Then Jesus, looking at him, loved him, and said to him, "One thing you lack: Go your way, sell whatever you have and give to the poor, and you will have treasure in heaven; and come, take up the cross, and follow Me."
The rich man posed the question, "what must I do to inherit eternal life?" Jesus answered him and said, "Obey the commandments". Jesus was referring to the Ten Commandments (Mark 10:19). The man claimed that he had met the requirements of the law covenant since youth (Mark 10:20). Somehow, he still did not have peace about inheriting eternal life.
Jesus started with the first law, "One thing you lack: Go your way, sell whatever you have and give to the poor, and you will have treasure in heaven; and come, take up the cross, and follow Me." This was another way of saying, "do not put any other god's before me" (Exodus 20:3). The Bible then says in verse 22, "the rich man was sad at this word, and went away sorrowful, for he had great possessions." HE COULD NOT DO IT.
At the conclusion of this story, in verse 27, Jesus says, "With men it is impossible, but not with God; for with God all things are possible." You see, if you cannot do it; God wants you anyhow. God provided the most perfect sacrifice possible---the firstborn Son of God. The righteousness of any other creation falls short of this perfect standing and it is simply not possible for man to meet the requirements of the Ten Commandments. On the outside people may appear to meet these requirements, but in their heart---no way.
Jesus said in Matthew 23:26, "first cleanse the inside of the cup and dish, that the outside of them may be clean also." When you receive the righteousness of God by grace, you literally have His perfect righteousness inside of you. You have, "the Spirit of Him who raised Jesus from the dead" inside you. The Bible says in Romans 8:11, "But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ from the dead will also give life to your mortal bodies through His Spirit who dwells in you." If you want to change some bad behaviors, let God do it for you from inside.
As a believer, His Spirit is inside you. You need to fellowship with His Spirit---even while you sin on the outside. We sometimes think that we can only fellowship with the Holy Spirit when we are being righteous. It is when we sin that we need this fellowship the most. God does not love you less when you sin. He knew you were going to sin before you did. God wants the opportunity to change you. All you have to do is acknowledge His love, grace, and compassion---always. Talk to Him continually, you will see amazing results.
It makes no difference what size the issue is, God wants to make you completely free (Luke 4:18). The changes that He has made in my life are incredible.