How to Fight Sin by Faith

I said here that the way to defeat sin is to fight by faith - you must admit you can't overcome sin on your own and put your trust in God instead to do it. Here's how it works in practice: when you are tempted by any sin, don't think to yourself "I'm strong enough to beat this. I can hold out. I won't give in." That thinking is focused entirely on trusting yourself to be faithful and to be good. The problem with that is that we aren't good. No matter how much we try to do what is right, sooner or later we stray. Scripture makes it clear what our situation is: "for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus[.]" (Romans 3:23-24). We can't hope in our own ability to avoid sin; we have to accept instead that if we stand, we stand by the grace of God that comes through Christ.

This is the strength God wants us to draw on. "Finally, be strong in the Lord and in the strength of his might." says Paul in Ephesians 6:10. Instead of relying on our own strength or willpower, we need to rely on God's strength. So when temptation comes, turn to God in prayer and confess that you know you cannot do this on your own. Admit you need Him and are dependent on His power, and ask Him to strengthen you and to give you the grace to resist temptation. As Jesus said to His disciples: "Watch and pray that you may not enter into temptation. The spirit indeed is willing, but the flesh is weak." (Matthew 26:41). He did not say, "Strengthen your resolve and resist temptation." He told them to pray that they would not give in, asking God to keep them from sin.

The next step is crucial: you have to trust God that He will deliver you and grant you grace to resist. "In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one[.]" (Ephesians 6:16). It is faith in God that deflects and defeats the temptations hurled at us. One of the biggest reasons I found that sin was defeating me was because I had failed so many times before that I was just convinced it was hopeless to hold out forever. I was convinced that sooner or later I would fail anyway. But God tells us not to trust in our own limited strength, and to trust in His infinite, almighty power instead. The change here is huge. When you realize you're relying on God's power, you know that victory is possible! Jesus spent His whole life without ever sinning. If that's the power of God at work, then you can resist and overcome too. The confirmation of this is that God has promised us He will make us able to escape sin: "God is faithful, and he will not let you be tempted beyond your ability, but with the temptation he will also provide the way of escape, that you may be able to endure it." (1 Corinthians 10:13).

Fighting by faith means you take things one step at a time, trusting God to sustain you and give you strength to resist each temptation. You keep turning away from the temptation because you know that God is giving you the strength to succeed every time. And the reason this is different than trying to resist in your own strength is that you have asked God to deliver you and you have placed your faith in Him to do it. God responds to that trust and puts His power to work in your life to overcome sin. His power is inexhaustible and able to defeat anything.