One of the most appropriate prayers we should pray before any attempt to “lead” in worship is Psalm 51:
Be gracious to me, O God, according to your loving-kindness; according to the greatness of your compassion, blot out my transgressions. Wash me thoroughly from my iniquity and cleanse me from my sin. For I know my transgressions, and my sin is ever before me. Against you, you only, I have sinned and done what is evil in your sight, so that you are justified when you speak and blameless when you judge. Behold, I was brought forth in iniquity, and in sin my mother conceived me. Behold, you desire truth in the innermost being, and in the hidden part you will make me know wisdom. Purify me with hyssop, and I shall be clean. Wash me, and I shall be whiter than snow. Make me to hear joy and gladness. Let the bones which you have broken rejoice. Hide your face from my sins and blot out all my iniquities. 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. Restore to me the joy of your salvation and sustain me with a willing spirit (Psalm 51:1-12).
In order to engage in authentic, biblical worship, sin cannot be present in our lives. Sin disrupts everything. When we sin, we fail to conform to the moral laws presented in God’s Word. Furthermore, God hates sin because it contradicts his very nature of being eternally good. That’s why sin mars the image of God in our lives. We no longer reflect the nature God has designed us to reflect. While sin doesn’t change our standing before God, it does affect our fellowship with God because he is grieved by sin (Wayne Grudem, “Christian Beliefs,” p. 62). Therefore, our worship will be hindered until we repent of any sin in our lives. For we know that if we earnestly confess our sin, God is faithful and just to forgive us our sins and cleanse us from all unrighteousness (1 John 1:9).
Psalm 51 presents a proper method of biblical purification: remember God’s mercy, repent of your sin, and request God’s cleansing. We must come before God with a contrite heart, lamenting over sin and seeking purification from God. The Scriptures place great emphasis on purification from sin for the worshipper. The Psalmist says it this way: Who may ascend into the hill of the Lord? Who may stand in His holy place? He who has clean hands and a pure heart, who has not lifted up his soul to falsehood. He shall receive a blessing from the Lord and righteousness from the God of his salvation (Psalm 24:4-5). The author of Hebrews echoes this: Let us draw near to God with a sincere heart in full assurance of faith, having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water (Hebrews 10:22).
As a side note, I love reading books by the Puritan writers. One thing that has always stood out as a hallmark of these texts is their constant awareness of their sinful condition and their earnest desire for repentance. As I was recently reading a book of Puritan prayers, I came across an entry entitled “Purification.” This prayer is a healthy and necessary perspective on the need for purification as a worship leader:
“Lord Jesus, I sin. Grant that I may never cease grieving because of it, never be content with myself, never think I can reach a point of perfection. Kill my envy, command my tongue, trample down self. Give me grace to be holy, kind, gentle, pure, and peaceable. Deliver me from attachment to things unclean, from wrong associations, from the predominance of evil passions, from the sugar of sin as well as its gall, that with self-loathing, deep contrition, earnest heart-searching, I may come to thee, cast myself on thee, trust in thee, cry to thee, and be delivered by thee.”
(Taken from “Valley Of Vision,” p.81).