Let God be true and every man a liar.
When God calls a man and reveals Himself to that man, can anything prevent Him from doing so? No. Can you prevent God now? No.
When Christ Jesus was crucified for sin, did anything prevent Him from doing so? No. Can you prevent Him now? No.
When the Holy Spirit creates a new creature from a dead man, can anything prevent Him from doing so? No. Can you prevent Him now? No.
No man can prevent God from doing anything. The only problem we are presented with once we come to the Light, is continuing to walk in the spirit (believing God), or choosing to walk in the flesh (believing our own understanding). God is no longer dealing with us as servants of sin, but as children of righteousness. He began and will continue and complete what He Himself started in His child. You can't prevent Him from doing so. You can only believe Him or not.
If you think you were saved by any efforts of your own, you are choosing to walk in the flesh. And if you think you can keep yourself saved, you are choosing to walk in the flesh. Christ Jesus already accomplished salvation for us on the Cross and sanctifies us by His Spirit. We (our former selves) are crucified with Christ. The only dilemma now is, do you believe Him?
The only thing we can "cleanse ourselves" from is our own understanding. We have to keep putting off the natural flesh mind and choosing to put on the mind of Christ, to see as He sees. We have to choose to believe Jesus and not our own understanding of Him. We have to close our natural ears to the world (religious world, too) and listen to the Spirit of God.
“I thank God through Jesus Christ our Lord. So then with the mind I myself serve the law of God; but with the flesh the law of sin.” [Romans 7:25] Your natural mind, the flesh, cannot nor ever will submit to God, it’s impossible. You cannot make your outward man righteous, it’s dead. You can’t keep it righteous, it’s dead. You must come to that realization and humble yourself to God, submit your very thoughts to Him so you can see the truth. God rules a Christian’s life and there is nothing anyone can do to prevent Him from doing so.
The only alternative is not to believe Him. It won’t change the truth that Jesus Christ is Lord over you forever, but you will be choosing to walk blind to the truth.