When God’s Spirit gives us his presence and his salvation he also calls us to war. War with sin. War with our sinful nature. War with our flesh. War with ourselves. To grow is grace is, in part, to kill the flesh – the vestiges of our old nature. We are either feeding the flesh and starving the Spirit, or feeding the Spirit and starving the flesh.
The Puritans called this mortifying the flesh. “Do you mortify; do you make it your daily work; be always at it while you live; cease not a day from this work; be killing sin or it will be killing you” (John Owen, Overcoming Sin and Temptation). Most Christians acknowledge this warfare as necessary and we give passing attention to it, but …. That but is the problem. We fight our sin like we fight our favorite unhealthy food; occasionally, half-heartedly, and with a secret plan to taste it again.
But this duel to the death with sin in not merely an old Puritan obsession, it is a Biblical command. “For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live” (Romans 8:13). “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” (Galatians 5:17). We have been set free from the guilt and shame of sin, and we are being delivered from the power and presence of sin. “If you by the Spirit you put to death the deeds of the body…” Romans 13. It is “by the Spirit” that we kill sin. We are not left to our own resources, we have the full armor of God (Ephesians 6:10-20), but we must put the armor on and enter the lists. We are passionately active in this duel with our sin. God works in us and with us, but in sanctification, He will not work without us.
The Hebrew Christians had suffered greatly for their commitment to Jesus as their Messiah. They “endured a hard struggle” “being publicly exposed to reproach and affliction.” They had “compassion on those in prison” and they “joyfully accepted the plundering of (their) property” Hebrews 10:32-34. They were in the trenches, standing with Christ and supporting his people. But they were wavering, and uncertain because following Christ was increasingly difficult. Yet, even in their sincere difficulty, they are exhorted to fight sin. “In your struggle against sin, you have not yet resisted to the point of shedding your blood” (Hebrews 12:4).
It is football season and you can always tell who is winning by glancing at the scoreboard. So, how are you doing in your battle with sin? Are you on the gridiron with your pads, your fresh bruises, and your blood, sweat, and tears? Or are you in the stands, with a greasy burger and a cold beer watching your team lose? What is the score? Brothers and sisters, to arms! The war is won, but our battle remains. Kill sin, or it will kill you.