“Out with the Bad, In with the Good”
"When the unclean spirit has gone out of a person, it passes through waterless places seeking rest, and finding none it says, ‘I will return to my house from which I came.’ And when it comes, it finds the house swept and put in order. Then it goes and brings seven other spirits more evil than itself, and they enter and dwell there. And the last state of that person is worse than the first."
Though I don't believe demons have the power to possess people today as they did in the first century, Jesus is giving us a timeless principle in the above verses: for positive change to become habitual and character forming, we must not only kick out the bad but also replace the bad with the good. The Christian life is not merely about the cessation of evil. The apostle Peter, quoting David in Psalm 34, says to those who desire "to love life and see good days, turn away from evil and do good; let him seek peace and pursue it." (1 Pet. 5:10)
Christian character cannot develop within us if we focus on "sin management" and fail to do the positive, good works of Christ. As Jesus says, the danger of this one-sided approach is that the "last state of that person is worse than the first." People who were once believers can become rabid skeptics. The addict who does well for a while is crushed by relapse. Faith which eagerly springs forth can wither and die on the vine.
The Colossian Christians were in danger of falling for this very thing. Merely trying to keep oneself from sinning by submitting to certain regulations and creating new restrictions for oneself is not enough. The apostle Paul warned them that "these have indeed an appearance of wisdom in promoting self-made religion and asceticism and severity to the body, but they are of no value in stopping the indulgence of the flesh." (Col. 3:23) He immediately went on to encourage them to think through the realities of their salvation. They had been "raised with Christ," therefore they must "seek the things that are above, where Christ is" (Col. 3:1). It's not just about abstaining from what is wrong ("put off the old self..." Col. 3:5-9). It's also about pursuing what is right ("put on the new self..." Col. 3:10-17).
For holiness to be real and sustainable, it must include both separation from evil and embracing good, both repentance and consecration, both putting off and putting on. Notice Paul's words to the Romans address both sides of the issue: "abhor what is evil; hold fast to what is good" (Rom. 12:9); "do not be overcome by evil, but overcome evil with good" (Rom. 12:21); "be wise as to what is good and innocent as to what is evil" (Rom. 16:19). It is impossible to "not love the world or the things in the world" (1 Jn. 2:15) if we are not constantly setting our "minds on things that are above" (Col. 3:2).
Christ fixes our bad habits by replacing them with good ones. This is Christ's work of new creation within us (2 Cor. 5:17). Let us cooperate with him, so that he can "bring [that work] to completion at the day of Jesus Christ" (Phil. 1:6). "Therefore, my beloved, as you have always obeyed, so now, not only as in my presence but much more in my absence, work out your own salvation with fear and trembling, for it is God who works in you, both to will and to work for his good pleasure." (Phil. 2:12-13)