Romans 8:13 “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.”
What Mortification is NOT
With that being said, we must make it our constant duty to kill sin whenever it rears its ugly head. Before we actually describe this process of mortification, it would be helpful for us to clearly delineate what mortification is NOT. First of all, mortification is not just a cosmetic makeover of our sin. What is meant by this? The Bible often speaks of “root” sins and “fruit” sins. Root sins are those deeply ingrained sins that lie way beneath the surface such as pride, lust, selfishness, and idolatry. Fruit sins are those outward expressions of sin that we often equate with sinning such as lying, murder, theft, and adultery. Many attempts to manage sin only deal with the fruit sins instead of getting down to the root sins. It is nothing more than a makeover with window dressing in order to cover the problem, but never getting down to the depths of the problem.
For example, Gary struggles with pornography and stays up late filling his mind with illicit images while his unsuspecting wife is asleep. In order to deal with this problem, Gary tackles the issue of pornography and may use legalistic measures to somehow stop him from surfing the internet. He may slap his hand every time he wants to click on a porn site. His fruit problem is pornography, but his root problem is lust. He may eventually “get over” the pornography problem, but since lust has not been killed at the root, it may manifest itself in another outward fruit such as adultery or visiting massage parlors while on a business trip. Diverting sin is not enough. Covering it up is not enough. Mortification involves killing the sin at its root.
Secondly, ignoring sin and hoping that it goes away is also hazardous and does not truly describe the process of mortification. John Owen aptly illustrates the problem with ignoring sin by saying, “Such a one never thinks his lust dead because it is quiet; but labors still to give it new wounds, new blows every day.” We must never get to the point where we think sin is inert within us just because we may not be experiencing a particular struggle for a season. Sin deceitfully lies dormant but like a cobra it springs forth with a venomous attack and will seek to destroy us when we least expect it.
Thirdly, occasional attempts will not successfully work in this process of mortification. We cannot be haphazard nor inconsistent. We may be diligent for a period of time in killing sin and then let up in the fight and just coast. When we get in this posture of relaxation, we tend to drift toward apathy in our response to sin. As a result, we get lulled into a sinister sleep and we may only practice mortification in a hit and miss fashion. John Owen again reminds us: “But now let the heart be cleansed by mortification; the weeds of lust constantly and daily rooted up, as they spring daily, nature being their proper soil; let room be made for grace to thrive and flourish; how will every grace act its part, and be ready for every use and purpose!”