As the weather has gotten warmer, the dog’s old arch nemesis has begun to appear: the flea! Fleas make me seriously crazy. I hate them! I hate them for what they do to the dog. And they can bite me, too.
So I fly into action. Fighting fleas is an all-out, ongoing battle for me, one of regular, consistent effort. I start by immersing my bewildered (and not too thrilled) puppy in warm, soapy water. Immediately there’s a small victory: one or more fleas float off into the water. 
Photo credit: kidsrelaxation.com
Hurray! But that’s just one skirmish.
After that it’s vacuuming, baking soda brushed into the carpet to kill the fleas that may be living there. And vacuuming later. And vacuuming some more. I’m going the natural route this year: lavender oil, a dilution of lemon juice and rosemary, sprayed on and rubbed into the dog’s skin. At the very least, the apartment smells floral.
But I am hoping for more than just a surface shine. I’m hoping for real results. Dogs that don’t constantly chew or abruptly turn and bite at themselves. I feel like this is similar to our battle with sin. It’s not a “fire it and forget it” kind of war, like dropping an atom bomb. 
Before it begins: Part of the effort is in prevention. Killing it before it becomes full grown and capable of creating havoc. I don’t want to just overlook or bury the sin and think I’m okay because I can’t see it. Spiritually speaking our prevention is prayer and being in the Word!
The daily battle: It’s every day, scouring and scrubbing. Just when you think you’re “okay” is when you may get a surprise. Keeping a vigilant watch to see if you can actually catch the flea (sin). If you find it has started to (or already) become full grown, then your weapons are prayer, confession, and repentance. Seek the Lord’s help in forsaking this.
Whoever conceals his transgressions will not prosper, but he who confesses and forsakes them will obtain mercy. [Prov. 28:13 ESV]
I acknowledged my sin to You, And I did not cover my iniquity; I said, “I will confess my transgressions to the LORD”; And You forgave the iniquity of my sin. [Ps. 32:5 ESV]
Just as you have varying degrees of skirmishes with fleas, so it is with sin. You will never completely eradicate sin in this life.
8 If we say we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. [1 John 1:8-9 ESV]
Like fleas that try to run and hide as you attempt to catch them with your fingers (almost a miraculous impossibility), your sin nature tries to run and hide itself. It builds up walls of rationalization as to why what you’re doing “isn’t that bad,” why you have the “right to do it” in your Christian freedom, to convince you it’s okay because “other people do it.” These are the moments when you ask, but what is ruling my heart? 
Sinclair Ferguson puts the process of fighting sin aptly when he says:
“It is the constant battle against sin which we fight daily–the refusal to allow the eye to wander, the mind to contemplate, the affections to run after anything which will draw us from Christ. It is the deliberate rejection of any sinful thought, suggestion, desire, aspiration, deed, circumstance or provocation at the moment we become conscious of its existence…. It is not accomplished only by saying ‘no’ to what is wrong, but by a determined acceptance of all the good and spiritually-nourishing disciplines of the gospel.”
— from The Christian Life, 150
Fighting sin is not easy and it can be exhausting. That’s why you have to take more serious measures than just a finger’s worth of strength. Happily we have that strength and power in God’s Spirit.
But I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. [Gal. 5:16-17 ESV]
Stand in the Storm 