The true believer’s response to the gospel of Jesus Christ is to pursue a radical transformation of the heart and mind in order to be conformed to the image of God in Christ (Col. 3:10). The central endeavor of this response is repentance. Repentance is the necessary response to the gospel through faith, as both faith and repentance are mutually congruent and inseparable. Repentance necessarily entails the pursuit to arrest and vanquish our innate corruption while intentionally pursuing a newness of life in the likeness of Christ. The former is what the Scriptures call mortification, and the latter, vivification. Johannes Wollebius refers to these two acts as the “turning away from evil and turning toward good.”
The impetus behind this article concerns whether our present notions and efforts of mortification have become too cursory. Today, there is a trend to view mortification as nothing more than the self-discipline not to act on one’s sinful desires but also embracing them as a matter of identity of one’s “brokenness.” But this is not biblical repentance, as unbelievers also advocate such things. True mortification of sin involves much more than this, and its importance and practice cannot be neglected. Mortification is an essential part of biblical repentance and will ultimately serve as a reflection of whether we have truly been regenerated by the Holy Spirit. Any enduring repudiation of the work of mortification could mark one’s profession of regeneration and faith as dubious. So the question is, What is mortification?
The Essence of Mortification
To mortify means to put to death. There are two words in the New Testament Greek which reveal the nature of mortification. They are thanatoute and nekrōsate from Romans 8:13 and Colossians 3:5, respectively. The essence of what it means to mortify one’s sinfulness is the intentional effort to strike down and put to death our corrupt sinful nature and its desires. Puritan author John Owen, in his classic work On the Mortification of Sin, expounded on these scriptural commands to put to death the deeds of the body. According to Owen, mortify means not the mere cessation of external sinful deeds but “the deeds of the flesh in their causes from whence they spring.” This is where the ax of mortification is to be employed—at the root of our sin. Just as a firefighter quenches a fire by aiming their extinguisher not at the tips of the flames but rather at the base of the fire.
This is a radically different view from merely restraining one’s sinful desires in an attempt to keep them from becoming actions. This latter view only advocates the suppression of sinful impulses. Biblical mortification calls for a spiritually lethal effort. And the target is our corrupt and depraved nature and its desires. For this to take place, a change must be wrought in us.
In regeneration, our souls are renewed from death to life by the power of Holy Spirit. This is where the Scriptures speak of our being “made alive,” “quickened,” “having our eyes opened,” and “given the Spirit of wisdom and of revelation in the knowledge of Him to lead to us walk in His statutes.” In regeneration, we are made aware of our corruption and sinfulness before God and its consequences concerning divine judgment. And with this understanding also comes a deep contrition of the heart, sorrow for the sins in one’s soul, and an increasing hatred and abhorrence for them. This serves as the basis for the Holy Spirit’s continual work of mortification in the lives of each person who is truly born again.
The Necessity of Mortification
Jesus clearly emphasizes the necessity of mortification when He says: “I tell you, no, but unless you repent, you will all likewise perish” (Luke 13:3). This command from our Lord needs to be heeded with all seriousness. Without genuine repentance, any profession or devotion to Christ and His gospel or the Christian life, however auspicious, will not result in the eternal salvation of one’s soul. The entire Christian life is marked by an enduring conflict between our new Spirit-granted hearts that want to do good and the remaining presence of sin that wars against them (Rom. 7:14–25). In Romans 8:13, we are told, “For if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live.” The structure of this verse is to convey two points which are mutually exclusive, and each point is conditional in form. In the first condition, if people are still living according to the flesh—as unbelievers do—they will die. There is no possibility that they will live unless they are born again and cease living according to the flesh. The second condition shows that if people endeavor by the Spirit to mortify their sinful natures and their evil desires throughout their lives, then they will live.