The mission of the church is to “make disciples of all nations.” Among other things, making disciples involves “teaching [converts] to obey everything I [Jesus Christ] have commanded you” (Matthew 28:19-20). Notice carefully Christ’s words: The church makes disciples by teaching them how to behave, not merely what to believe. Following Christ is a way of life.
We should not think of it as an individual way of life, however. It is social. This is evident in baptism, the first act of discipleship. Christ commands the church to baptize would-be disciples “in the name of the Father and of the Son and of the Holy Spirit” (verse 19). To fulfill its mission, the church needs converts to baptize. And to obey the commands of Christ, converts need a church to baptize them. To follow Christ, then, is to follow him with others in a relationship of mutual dependence.
This relationship of mutual dependence is both positive and negative. Positively, members of the church teach one another. Paul writes, “Let the word of Christ dwell in you richly as you teach and admonish one another with all wisdom, and as you sing psalms, hymns and spiritual songs with gratitude in your hearts to God” (Colossians 3:16).
Negatively, members of the church hold one another accountable through discipline, including excommunication if necessary.
Even though I am not physically present, I am with you in spirit. And I have already passed judgment on the one who did this, just as if I were present. When you are assembled in the name of our Lord Jesus and I am with you in spirit, and the power of our Lord Jesus is present, hand this man over to Satan, so that the sinful nature may be destroyed and his spirit saved on the day of the Lord (1 Corinthians 5:3-5).
Modern readers of this passage are offended by Paul’s language of judgment and destruction. So an analogy might be helpful. To be a lawyer, a person must complete law school, pass the state bar exam, complete Mandatory Continuing Legal Education, and fulfill various legal and ethical requirements outlined by the bar. If a lawyer fails to do these things, she can be disciplined and, in extreme cases, disbarred. The promise of remaining a member of the state bar and the threat of disbarment act, respectively, as incentive for good behavior and disincentive for bad behavior.
Christian discipline is similar, and its purpose is redemptive, not punitive. In other words, the goal of discipline – even of excommunication – is to help people renew their followership of Jesus Christ. Paradoxically, according to Paul, discipline destroys the “sinful nature” in order to save the “spirit.” The threat of excommunication disincentivizes bad behavior. The promise of inclusion incentivizes obedience to Christ.
Here’s the hard question modern Christians must ask themselves after reading this passage: Is the quality of our life together so good that people would rather repent of their sins than lose membership in it. If not, why not?
GeorgePWood.com 
George,
That is an excellent and challenging question. Let me pose a counter thought.
-Isn’t our Christian disunity an obvious determent to excommunication being an effective means of discipline? I believe even Fee, though making note of this same question, doesn’t then move to the fundamental necessity of a recovery of visible unity. Paul here shows that if one can just hop down the road to another church, then our concrete realization of “the Church” is subChristian. For instance, in the RCC this is technically still realizable; ought this not challenge our unreconciled state?
So on the one hand our Christian life is such that it doesn’t incentivize repentance, and on the other, our disunity makes such a point near moot.
Tony:
The answer to your question is, unfortunately, yes, though unlike you, I wouldn’t exempt the Catholic church, which long before the Reformation suffered the Great Schism and Avignon papacies.
By the way, and apropos of your latest Theophiliacs post, I hope my complex sentences satisfy your Latinate predelictions.
George
George,
Oh, I didn’t mean to imply that the RCC hasn’t played a massive part in Christian division, they have at many points. I meant merely that their dedication to the “visible” Church is such that excommunication can still work. For example, if a priest received a new Roman catholic parishoner, they’d have recourse to information from their previous parish; and if a non-RC came they’d have to go through the proper process. So at least in theory, within the RCC, the structure for this is still in place.
And you are a fine rhetoritician.
I think part of the problem in our modern society may be the size of churches. I attended a large church for many years. Accountability is difficult to attain in that setting. I now attend a much smaller church and am, I believe, more aware of how my obedience or lack thereof impacts others and vice versa.