Ps. 51:10-12 Create in me a clean heart, O God. Renew a right spirit within me. Do not banish me from your presence, and don't take your Holy Spirit from me. Restore to me again the joy of your salvation, and make me willing to obey you.
This is a prayer that when prayed sincerely God will answer every time. There is no greater need in life than to have a clean heart before God. Sin dirties up the soul. It puts up a barrier between God and us and it won't go away on its own. We must have God's help in order to get rid of it. Only the righteousness of Christ can make our heart pure before God. This is a prayer every believer should live by. We should always desire to have pure hearts before God.
When we sin there is something drastically wrong with our spirit. The decision to sin indicates that things are out of kilter with God. It means that we have neglected our soul. It means that we have not stayed close to God like we must. We have neglected His Word and failed to spend time alone with Him in prayer.
If nothing is done about it, God will have no choice but to banish us from His presence. A sinful soul that will not repent cannot draw near to God. God is holy and will never let sin go unpunished. A broken and contrite heart enables God to forgive us and wash away our sin. Unconfessed sin prevents the Holy Spirit from working in us. God cannot help us as long as we insist on defying Him by harboring our sin in our hearts.
The joy of salvation floods the repentant soul. There is great relief and rejoicing in knowing that the soul is right with God. There is not only renewed fellowship with God, there is a renewed willingness to obey Him. There is a real desire that when faced with the same temptation again to not yield to it. There is a desire to do what is right with God and not what is right in our own eyes. Obedience follows repentance every time.