The world, the flesh, and the devil. Our three enemies. Battles on three fronts. How do we win? How do we keep up our guard?
Remember that the old man has been crucified in Christ. We have put off the old man, Paul tells us, and so therefore we are to put off the ornaments, the clothing of the old man. And having put on Christ, we are to put on the garments of the new man. We are to put off lying, for instance, and put on the truth. We are not to get drunk with wine, for that is dissipation, but we are instead to be filled, overcome with the Spirit. We are to put off all forms of fornication and put on lives sexual purity, either in celibacy or in the marriage bed as defined by the Lord.
The world and the devil are strong enemies. But they are external. They cannot make great gains against our sanctification unless we first yield to the flesh – our fleshly desires. There is no reigning sin in a Christian – or else he really isn’t converted. But there is the problem of remaining sin and that is where the internal battle rages.
And so we are instructed to mortify that flesh – and to do so daily. We do so by faith and in the power of Christ in us, the hope of glory. In other words, do not battle flesh with flesh. Battle flesh with the Spirit. Do not allow the flesh to lease a space in your heart for a time – that internal enemy will open the door to the other two external enemies when you aren’t watching. Every time the works of the flesh start showing up in your heart, escort them out immediately in the name of Jesus. We are to have no place for it to reside, to rest, to make itself comfortable or for us to be comfortable with.