Write: below "Sin has no power over me, <insert your name here>!"
Repeat: this to yourself throughout your day as a man saved by grace.
“Let not sin therefore reign in your mortal body, to make you obey its passions. Do not present your members to sin as instruments for unrighteousness, but present yourselves to God as those who have been brought from death to life, and your members to God as instruments for righteousness. For sin will have no dominion over you, since you are not under law but under grace.”—Romans 6:12-14
I know you have been discouraged because you can't overcome a repetitive sin. You feel the pain of defeat each time you give into that all too familiar temptation. In desperation, sometimes you will cry out to God for deliverance from your "mortal" experience. But within the confines of your mind, you know that you will only succumb to "obey its passions" once again.
But remember as God's man, you are not to "present your members to sin as instruments for unrighteousness." And by choice, you do not live as a prisoner to the old "law"but under the freedom of a new system of "grace.""Under grace" you have independence from the damnation of this sin, and also the power to overcome repetitive sin cycles. And yet even in the face of the occasional failure, you have victory, not one that abuses the grace you have been given but one where "sin will have no dominion over you."