Perhaps the greatest key to overcoming besetting sin is humility, or living for God’s glory not our own.
Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God.1 Corinthians 10:31
The purpose of the Christian life is to glorify God. This means that we are to show how great God is in every aspect of our lives. However, our sinful nature demands that we be glorified not God. In other words every aspect of our lives can be boiled down to this, “Will you be praised for _____, or will God be praised?” For example, either your cooking, work ethic, etc. will be praised for the food you eat or God’s provision, wisdom, and grace will be praised for the food you eat. This is especially important when it comes to overcoming sin.
For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called: But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty; And base things of the world, and things which are despised, hath God chosen, yea, and things which are not, to bring to nought things that are: That no flesh should glory in his presence. But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption: That, according as it is written, He that glorieth, let him glory in the Lord.1 Corinthians 1:26-31
For my name’s sake will I defer mine anger, and for my praise will I refrain for thee, that I cut thee not off. Behold, I have refined thee, but not with silver; I have chosen thee in the furnace of affliction. For mine own sake, even for mine own sake, will I do it: for how should my name be polluted? and I will not give my glory unto another.Isaiah 48:9-11
God chose to save the weak, sinful, and despised so that He would receive all of the glory. You will only be delivered from your besetting sin if God is going to get all the glory for it. Herein lies perhaps the greatest secret for victory, “If you no longer committed your besetting sin, would God be glorified or would you be glorified?” You see, we want to be seen as more spiritual than what we are, so we pretend as if we do not sin. When we gain victory over sin we want it to appear that we either never struggled to begin with or that we overcame by the power of our own will. This is why we do not walk in victory. God will not share His glory with us.
And he spake this parable unto certain which trusted in themselves that they were righteous, and despised others: Two men went up into the temple to pray; the one a Pharisee, and the other a publican. The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican. I fast twice in the week, I give tithes of all that I possess. And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.Luke 18:9-14
And when they entered unto the heathen, whither they went, they profaned my holy name, when they said to them, These are the people of the LORD, and are gone forth out of his land. But I had pity for mine holy name, which the house of Israel had profaned among the heathen, whither they went. Therefore say unto the house of Israel, Thus saith the Lord GOD; I do not this for your sakes, O house of Israel, but for mine holy name’s sake, which ye have profaned among the heathen, whither ye went. And I will sanctify my great name, which was profaned among the heathen, which ye have profaned in the midst of them; and the heathen shall know that I am the LORD, saith the Lord GOD, when I shall be sanctified in you before their eyes. For I will take you from among the heathen, and gather you out of all countries, and will bring you into your own land. Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you. A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.Ezekiel 36:20-27
Why does God deliver people from their sin? For His own name; for His own glory. If you desire for God to move on your behalf you must choose to live for His glory, not your own.