In Ps 51, David asked the Lord to cleanse him from his sin, v.2.  He prayed “purge me… and I shall be clean”, v.7.  And he prayed, “Create in me a clean heart, O God”, v.9.  He was cleansed from sin.

How can I be cleansed from sin?

By getting saved – 1 Cor 6:9-11.  We are sanctified by the Spirit at salvation 1 Cor 6:11.  God so cleanses you from sin at salvation that you are not what you used to be; you are a new creature in Christ.

By separating from the unclean – 2 Cor 7:1.  We must cleanse ourselves by separating from the unclean. The context of 2 Cor 7 is 2 Cor 6:17-18.  See 2 Pet 2:18-21.  When we’re saved we are clean had escaped from them who live in error.  We must not go back.  And in 2 Tim 2:19-21 we need to purge ourselves from iniquity and vessels of dishonor.

By abstaining from sin – 1 Thes 4:3-5 the will of God is your sanctification, that ye should abstain from fornication…. Take the option to sin off of the table.

By confessing my sin – 1 Jn 1:7-9.  The Lord cleanses us from all unrighteousness when we confess our sins, 1 Jn 1:9.  When we agree with God, in confession, about a particular sin that has adversely affected our fellowship with him, he cleanses us and restores our fellowship.

By heeding the word – Jn 17:17.  Sanctify them through thy truth: thy word is truth.  See Jn 15:3; Eph 5:26.  Heed it Ps 119:9.  Bob Jones Sr said, “This book will keep you from sin or sin will keep you from this book”.

By pleading the blood – Heb 9:23-24.  How much more shall the blood of Christ… purge your conscience….  Plead the blood concerning something that’s wounding your conscience or stirring up wicked imaginations in your heart.  In essence, you’re asking God to put what you’re thinking about on full display in front of his throne so he can purge it with his blood.  When you do this, the wicked thought is obliterated by the blood of Christ.

Conclusion: if you will follow these scriptures, you will see God cleaning up the sin in your life.  You will be cleansed from sin.  Sin won’t be gone completely, because we are still in this flesh.  But you will certainly be cleaner and in better fellowship with the Lord.