It is God who sanctifies us, we can't sanctify ourselves, The only good thing we have is the Holy Spirit dwelling inside us. (Psalm 16:2 My goodness is nothing apart from You). (2 Tim 1:14 Kept by the Holy Spirit who dwells in us). (1 Thes 5:23 Now may the God of peace sanctify you completely, and may your whole spirit, soul and body be preserved blameless at the coming of our Lord Jesus Christ). We must depend and trust on Jesus's righteousness and not our own, Our righteousness is as filthy rags. (Phili 3:9 and to be found in Him, not having a righteousness of my own, which is from the law, but that which is through faith in Christ, the righteousness which is from God by faith).
when you think you are doing something it is not you, it is God working through you, or else we would have grounds for boasting. Once again we have no righteousness apart from God. The apostle Paul said i know that within me, that is my flesh NO GOOD THING DWELLS (Romans 7:18). (John 15:5 apart from Me you can do nothing). It is God who sanctifies us (1 Thes 5:23) , His Spirit inside us. The body is dead because of sin, but the Spirit is life for because of righteousness (Romans 8:10). (2 Corth 4:7 But we have this treasure in earthen vessels, that the excellence of the power may be OF GOD and NOT US). Also Luke 17:10.