I recently read this in Sinclair Ferguson’s book, In Christ Alone: Living the Gospel Centered Life.  I thought that it was very good and was worth the time to post it.  I hope that you enjoy it!

“The aftermath of a conversation can change the way we later think of its significance. My friend-a younger minister-sat down with me at the end of a conference in his church and said, “Before we retire tonight, just take me through the steps that are involved in helping someone mortify sin.” We sat talking about this for a little longer and then went to bed; I hoped he felt as blessed as I did by our conversation.

I still wonder whether he asked his question as a pastor or simply for himself-or both.

How would you best answer his question? The first thing to do is to turn to the Scriptures. Yes, turn to John Owen (never a bad idea!) or to some other counselor dead or alive. But remember that we have not been left only to good human resources in this area. We need to be taught from “the mouth of God” if the principles we are learning to apply are to carry with them both the authority of God and the promise of God to make them work. Thus our Lord Jesus Himself believed (Matt. 4:4).

Several passages come to mind for study: Romans 8:13; Romans 13:8-14 (Augustine’s life-transforming text); 2 Corinthians 6:14-7:1; Ephesians 4:17- 5:21; Colossians 3:1-17; 1 Peter 4:1-11; 1 John 2:28-3:11. Significantly, only two of these passages contain the verb mortify (“put to death”). Equally significantly, the context of each of these passages is broader than the single exhortation to put sin to death. As we shall see, this observation turns out to be of considerable importance.

A Good Starting Place
Colossians 3:1-17 is probably the best place for us to begin. The believers in Colossae were relatively young Christians. Theirs had been a radical experience of conversion to Christ from paganism. They had entered a gloriously new and liberating world of grace. In fact, perhaps-if we may read between the lines-they had felt for a while as if they had been delivered not only from sin’s penalty but even from its influence, so marvelous was their new freedom. But then, of course, sin reared its ugly head again. Having experienced the “already” of grace, they were discovering the painful “not yet” of ongoing sanctification. Sound familiar? Just at this point keen young Christians can be all too vulnerable to “quick fixes.”

But as in our evangelical subculture, quick fixes do not solve long-term problems. Unless the Colossians gained a firm grasp of gospel principles, they were at risk of falling prey to false teachers with promises of a higher spiritual life. That was what Paul feared (Col. 2:8, 16). Holiness-producing methods were in vogue (Col. 2:21-22). Moreover, they seemed to be deeply spiritual, just the thing for earnest young believers. But, in fact, says Paul, such things “are of no value against the indulgence of the flesh” (Col. 2:23).

Not new methods, but only an understanding of how the gospel method works, can provide an adequate foundation and pattern for dealing with sin. This is the theme of Colossians 3:1-17.

Paul gives us the pattern and rhythm we need. Like Olympic long jumpers, we will not succeed unless we go back from the point of action to a point from which we can gain energy for the strenuous effort of dealing with sin.

How, then, does Paul teach us to do this?

NEW IDENTITY
First of all, Paul underlines how important it is for us to be familiar with our new identity in Christ (3:1-4).

How often, when we fail spiritually, we lament that we forgot who we really were.

Christians have a new identity. We are no longer “in Adam” but “in Christ”; no longer in the flesh but in the Spirit; no longer dominated by the old creation but living in the new (Rom. 5:12-21; 8:9; 2 Cor. 5:17).

Paul takes time to expound this:
• We have died with Christ (3:3; we have even been buried with Him, 2:12).
• We have been raised with Christ (3:1).
• Our true life is hidden with Christ in God (3:3).
• We are so inseparably united to Christ that we will appear in glory with Him (3:4).

Failure to deal with the presence of sin can often be traced back to spiritual amnesia-forgetting our new, true, real identity. As a believer, I am someone who has been delivered from the dominion of sin and who therefore is free and motivated to fight against the remnants of sin in my heart. You must know, rest in, think through, and act upon your new identity-you are in Christ.

SIN EXPOSED
Second, Paul goes on to expose the workings of sin in every area of our lives (Col. 3:5-11). If we are to deal with sin biblically, we must not make the mistake of thinking that we can limit our attack to only one area of failure. All sin must be dealt with. Thus, Paul ranges through the manifestation of sin in private life (v. 5), everyday public life (v. 8), and church life (vv. 9-11; “one another” and “here” indicate the church fellowship).

The challenge in mortification is akin to the challenge in dieting (itself a form of mortification!). Once we begin, we discover that there are all kinds of reasons we are overweight. We are really dealing with ourselves, not simply with calories. I am the problem, not the potato chips! Mortifying sin is a whole-of-life change.

PRACTICAL GUIDELINES
Third, Paul’s exposition provides us with practical guidance for mortifying sin.

Sometimes it seems as if Paul gives exhortations (“Put to death. – – ,” 3:5) without giving “practical” help to answer our “how-to” questions. Often today Christians go to Paul to tell them what to do and then to the local Christian bookstore to discover how to do it!

Why this bifurcation? Probably because we do not linger long enough over what Paul is saying. We do not sink our thinking deeply into the Scriptures. For, characteristically, whenever Paul issues an exhortation, he surrounds it with hints as to how we are to put it into practice.

This is certainly true here. Notice how this passage helps to answer our “how-to” questions.
1. Learn to admit sin for what it really is. Call a spade a spade-call it “fornication” (v. 5), not “I’m being tempted a little”; call it “uncleanness” (v. 5), not “I’m struggling with my thought life”; call it “covetousness, which is idolatry” (v. 5), not “I think I need to order my priorities a bit better.” This pattern runs right through the whole section. How powerfully it unmasks self-deception-and helps us to unmask sin lurking in the hidden corners of our hearts!
2. See sin for what it really is in God’s presence. “Because of these the wrath of God is coming” (3:6). The masters of the spiritual life spoke of dragging our lusts to the cross (kick and scream, though they will), to a wrath-bearing Christ. My sin leads not to lasting pleasure but to holy divine displeasure. See the true nature of your sin in the light of its punishment. Too easily we think that sin is less serious in Christians than it is in unbelievers: “It’s forgiven, isn’t it?” Not if we continue in it (1 John 3:9)! Take a heaven’s-eye view of sin and feel the shame of that in which you once walked (3:7; cf. Rom. 6:21).
3. Recognize the inconsistency of your sin. You have put off the “old man,” and have put on the “new man” (3:9-10). You are no longer your “old self.” The identity you had “in Adam” is gone. The “old man was crucified with Him [Christ], that the body of sin [probably meaning “life in the body dominated by sin”] might be done away with, that we should no longer be slaves of sin” (Rom. 6:6). New people live new lives. Anything less than this is a contradiction of who we are “in Christ.”
4. Put sin to death (v. 5). It is as “simple” as that. Refuse it, starve it, and reject it. You cannot “mortify” sin without the pain of the kill. There is no other way!

But notice that Paul sets this in a very important broader context. The negative task of putting sin to death will not be accomplished in isolation from the positive call of the gospel to “put on” the Lord Jesus Christ (Rom. 13:14).

Paul spells this out in Colossians 3:12-17. Sweeping the house clean simply leaves us open to a further invasion of sin. But when we understand the “glorious exchange” principle of the gospel of grace, then we begin to make some real advances in holiness. Sinful desires and habits not only must be rejected but exchanged for Christ-like graces (3:12) and actions (3:13). As we are clothed in Christ’s character and His graces are held together by love (v.14), not only in our private lives but also in the church fellowship (vv. 12-16), Christ’s name and glory will be manifested and exalted in and among us (3:17).

These are some of the things my friend and I talked about that memorable Sunday evening.”

Sinclair Ferguson. In Christ Alone: Living the Gospel Centered Life (Kindle Locations 1826-1877). Kindle Edition.

For further reading:
Putting off involves fostering a new affection
The Expulsive Power of a New Affection by Thomas Chalmers