Create in me a clean heart, O God, and renew a steadfast spirit within me. Do not cast me away from your presence, and do not take Your Holy Spirit from me. Psalm 51:10,11
Cleansing the heart renews and restores our relationship with God and with man. Sin separates us from our heavenly Father and grieves the Holy Spirit. When we confess our sins, repent of our ungodly actions and make restitution with those we have defrauded or stolen from our heart is once again opened to communication to God and we are renewed in our mind and spirit.
Sin not only separates but it hardens the heart, sometimes to the point of no return making it impossible to feel the conviction of Holy Spirit's voice that leads us to repentance. The heart of man is the center of all spiritual life where God's Spirit dwells and where His presence resides and like a heart attack, sin damages our heart and our relationship with God and man. If God's Spirit is grieved away we have no more moral compass to guide us, leaving us cold and dark to the things of God.
Willful sin endangers us and can lead us to a sin unto death, in other words willful sinning can actually kill us if we continue to rebel against Holy Spirit's conviction for us to repent and be renewed. The apostle Paul rebuked the Corinthian church for allowing a young man to continue to commit adultery with His father's wife and for not exposing his sin before the congregation and ultimately turned him over to Satan for the destruction of his flesh, that his spirit may be saved, yet as through fire. We would do well to keep our hearts pure before the Lord and before man lest we suffer the same fate.
For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come, if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to open shame. Hebrews 6:4-6
Your servant in Christ, Tim Laughlin