Though we are commanded to 'wash ourselves', to 'cleanse ourselves from sins', to 'purge ourselves from all our iniquities', yet to imagine that we can do these things by our own efforts is to trample on the cross and grace of Jesus Christ. Whatever God works in us by his grace, he commands us to do as our duty. God works all in us and by us.
Without a sincere and diligent effort in every area of obedience, there will be no sucessful mortification of any one besetting sin.