I was reading an excerpt of a sermon by John Tillotson, archbishop of Canterbury in the late 1600's. This excerpt is from a book by John Baillie "A Diary of Readings." Let me give you some advice, go slowly; it is old English.
It is a fond thing for a man to think to set bounds to himself in any thing that is bad, to resolve to sin in number, weight and measure, with great temperance and discretion and government of himself; that he will commit this sin and then give over, entertain but this one temptation, and after that he will shut the door and admit no more.
To sin in hopes that hereafter we shall repent is do a thing in hopes that we shall one day be mightily ashamed of it, that we shall one time or other be heartily grieved and troubled that we have done it. It is to do a thing in hopes that we shall afterwards condemn ourselves for it, and wish a thousand times that we had never done it; in hopes that we shall be full of horror at the thoughts of what we have done, and shall treasure up so much guilt in our consciences as will make us a terror to ourselves, and be ready to drive us even to despair and destruction...'Tis just as if a man should be content to be ship wrecked, in hopes that he shall afterwards escape by a plank, and get safe to shore.
In other words, we say to ourselves, "let me play around one more time in my sin," or "let me stuff myself one more time, then after that I will feel so bad about it, I will be able to change." "I will not commit that sin anymore, or I will not stuff myself any more." So, whether that sin is stealing from work, looking at porn, lying to a friend, cheating on a test, getting drunk or high, etc, we hope that after this one last binge into the sin, we will be so angry with ourselves we will repent. To modernize Tilltotson's last statement, "let me drive drunk one last time, and after I crash, that will give me the impetus to stop drinking. We often play games with our sins and addictions. That is why the prophet Jeremiah wrote, "The heart is deceitful and beyond cure."
If I say, "I am going to begin a diet right after Christmas," my will power is already on shaky ground. Thus, when I do begin a diet, I will always come across another "right after." This is true with a diet and with sin. "I'm going to begin...right after..." often hardens our heart to the change and makes us less able to change.
As I am learning, as Alcoholics Anonymous has learned, and so many others have learned, we need to turn to God to help us overcome our sinful habit or addiction, and yes, even our diet. We need to be honest with him about our struggle. We can even tell him, "I don't want to change." But if we don't turn to him, we will probably continue to play games with ourselves and remain "stuck." So, we need to look to God to change our heart, so that our game playing will stop. And when the game playing stops, then the grace of God can enable us to begin experiencing victory.