From The Practice of Mortification
by Sinclair Ferguson

Here [in Colossae] were relatively young Christians. They have had a wonderful experience of conversion to Christ from paganism. They had entered a gloriously new and liberating world of grace. 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 almost 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 now discovering the painful "not yet" of ongoing sanctification. Sounds familiar!

But as in our evangelical sub-culture of quick fixes for long-term problems, unless the Colossians had a firm grasp of Gospel principles, they were now at risk! For just at this point young Christians can be relatively easy prey to false teachers with new promises of a higher spiritual life. That was what Paul feared (Col. 2:8, 16). Holiness-producing methods were now in vogue (Col. 2:21-22) -- and they seemed to be deeply spiritual, just the thing for earnest young believers. But, in fact, "they are of no value in stopping the indulgence of the flesh" (Col. 2:23). Not new methods, but only an understanding of how the Gospel works, can provide an adequate foundation and pattern for dealing with sin. This is the theme of Colossians 3:1-17.

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 "sexual immorality," not "I'm being tempted a little"; call it "impurity," not "I'm struggling with my thought life"; call it "evil desire, which is idolatry," not "I think I need to order my priorities a bit better." This pattern runs right through this whole section. How powerfully this unmasks self-deceit -- and helps us to unmask sin lurking in the hidden corners of 
our hearts!

2. See sin for what your sin really is in God's presence. "On account of these the wrath of God is coming" (3:6). The masters of the spiritual life spoke of dragging our lusts (kicking and screaming, though they be) to the cross, to a wrath-bearing Christ. My sin leads to -- not lasting pleasure -- but holy divine displeasure. See the true nature of your sin in the light of its punishment. Too easily do we think that sin is less serious in Christians than it is in non-believers: "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 (Col. 3:7; see also Rom. 6:21).

3. Recognize the inconsistency of your sin. You put off the "old man," and have put on the "new man" (3:9-10). You are no longer the "old man." The identity you had "in Adam" is gone. The old man was "crucified with him [Christ] in order that the body of sin [probably "life in the body dominated by sin"] might be brought to nothing, so that we would no longer be enslaved to sin" (Rom. 6:6). New men live new lives. Anything less than this is a contradiction of who I am "in Christ."

4. Put sin to death (Col. 3:5). 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 will begin to make some real advance in holiness. As sinful desires and habits are not only 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 life but also in the church fellowship (vv. 12-16), Christ's name and glory are manifested and exalted in and among us (3:17).

Read the entire article here.