First things first, as to not assume that all understand the term, I will provide a succint definition of mortification. Derived from Romans 8:13, mortification is that habitual process where a believer puts to death indwelling sin – i.e., he “takes away the principle of all [lust’s] strength, vigor, and power, so that [it] cannot act or exert or put forth any proper actings of [its] own.”
After Owen explains the exegetical basis of mortification (pp.45-49), the daily need for mortification (pp. 49-56), the causation of mortification being the Holy Spirit (pp. 57-62), the importance of mortification to a healthy spiritual life (63-67), and the nature of mortification (69-77), he gives two general principles that must lay the foundation for any man pursuing mortification. The first principle will be dealt with in this post, and the next will be addressed tomorrow.
1. There will be no mortification of sin unless one be a believer.
Owen’s exegetical basis is Romans ch. 8, so he must determine who is being addressed in that chapter as to communicate the proper application of mortification. ‘If you through the Spirit’ (Rom. 8:13) – who is the ‘you’ in that verse? Who is being urged to put to death the works of the flesh? Owen directs us to look back to 8:1. The ‘you’ of 8:13 is the same ‘you’ of 8:1. It is ‘you’ believers, ‘you’ to whom there is no condemnation.
“It is true, it is – it will be – required of every person whatsoever that hears the law or gospel preached, that he mortify sin. It is his duty, but it is not his immediate duty; it is his duty to do it, but to do it in God’s way.”
The gospel precedes mortification, because the Spirit is the only means of mortification, and the Spirit is only given through the gospel – by grace, through faith in Jesus Christ. “There is no death of sin without the death of Christ.” The unregenerate man’s immediate work is conversion, not mortification. Sin’s condemnation must first be loosed, and this is done through God’s justification of man. When Peter is asked what to do in response to the gospel, he does not say to mortify this and this sin; he calls them to repent and be baptized – be converted (cf. Acts 2:37-28). Mortification before conversion is like pruning thorns. No matter how much you prune a thorn, it still cannot bear fruit. ‘Make the tree good, and his fruit will be good’ (Matthew 12:33). “The root must be dealt with, the nature of the tree changed, or no good fruit will be brought forth.”
Practically, in dealing with unregenerate men, do not forsake addressing their sin; rather “drive it up to the head, and there deal with him. To break men off particular sins, and not to break their hearts, is to deprive ourselves of advantages of dealing with them.” This is not to deny the need of mortification. If anything, it is honoring its necessity more by properly giving men the correct path to pursue it. As Owen says, “I take not men from mortification, but put them up to conversion.”
Often, when an unregenerate man is convicted of his sin, instruction towards mortification before instruction towards conversion provides a great stumbling block. Mortification can become a diversion. Sure, “they set themselves to a relinquishment of sin, but not in that manner, by universal conversion, as God called for it.” They instead set themselves “to mortify the sin that galls him – which is a pure issue of self-love.” This latter point is better reserved for its analysis in the second general principle, which will be specifically addressed tomorrow.
 All quotations and references taken from Kelly Kapic and Justin Taylor’s edition: John Owen, Overcoming Sin and Temptation, ed. Kelly M. Kapic and Justin Taylor (Wheaton, IL: Crossway, 2006), 48.
 Owen, 79. My emphasis added.
 Ibid., 79.
 Ibid., 81.
 Ibid., 85
 Ibid., 84.
 Ibid., 82.
 Ibid., 82.