It seems to me, in my experience with these kinds of discussions, that people's misunderstandings about church discipline fall into a few categories:
1. They don't understand the nature of the Church.
2. They don't understand the nature of church membership.
3. They don't understand the seriousness of sin.
4. They don't understand the nature of church discipline.
Let's start with the first one. People who get their knickers in a twist about church discipline often seem to view "church" as an activity for people who call themselves Christians -- something they do on Sundays and Wednesday nights, a group they're a part of by choice, but nonetheless and organization that doesn't necessarily have the right to make any claims on their lives -- maybe slightly more that their book club or union or Facebook group, but not much more. They come to Sunday services to get blessed or "be fed" spiritually.
But what is the Church, really? Two things: 1) the Church is true followers of Christ everywhere, at all times throughout history, and 2) the Church is the local gathering of Christians in particular times and places. Paul's letters, for example, are written to both groups -- the church at Rome in the 1st Century A.D. and by extension to all believers everywhere at all times. Let me emphasize what I think is an extremely important point: if you are a Christian -- a genuine follower of Christ, not just a "Christian" by default -- you are, by necessity, a member of the first group. All believers at all times in all places are members of the first group. But the first and second categories were never meant to be thought of separately. Read Paul's letters and see if you think that the pioneer of the early church had any category in his mind for a person who was a Christian but not a part of any local church. (I'll give you a tip to save you a little time: he didn't.) It's not optional for a follower of Christ to be consistently out of fellowship with a local body. In fact (brace yourself, people, this is pretty serious), I would go so far as to say that if you steadfastly refuse to join yourself with a local congregation of believers, you are in serious danger of revealing that you are not a follower of Christ at all. And now I'm just going to back away... slowly... slowly...
That leads to the second misunderstanding. There is a whole group of folks in the church, as I mentioned in my previous post, who glance through their Bibles, don't see the word "membership," and conclude that any formal affiliation with a church is unnecessary at best and unbiblical at worst. First, I have bad news for those people -- the word "trinity" isn't in the Bible, either. Ruh-roh, Raggy.
Second, there is substantial evidence throughout the New Testament that the pastors of the early churches kept very precise, formal records of the believers they had charge of. I would basically defy anyone to do a careful study of the Jerusalem church in the book of Acts, the job description of an Elder in the pastoral epistles (1 and 2 Timothy and Titus), and Hebrews 13 and come away with the idea that it's cool for a believer to sorta hang out on the fringes of a church and never commit to it.
Side note: one of our teaching pastors, Daniel, tells a pretty great little story at the beginning of our membership classes about a guy who falls in love with this amazing, beautiful girl, spends all his time with her, can't shut up about her... and then three years later, they're still dating, but not married or even engaged. Of course she's frustrated, all his friends are saying, "What are you waiting for, dude?" but he keeps telling her, "We don't need to get married to prove I love you, right, baby?" Well, obviously the story is about us and the church. Of course we don't "need" to join a church to prove we love it, but we also can't reap the benefits of commitment unless we're actually committed!
Well, what are the benefits of commitment to a church, i.e. formal membership? First off, when a church admits you to membership, they're saying, "We testify to your salvation. We believe and acknowledge that you are a Christian." (Incidentally, this is one of the reasons why walk-the-aisle, sign-the-card "Baptist" membership is so pernicious -- if your pastors don't examine you and make sure you're actually saved, how on Earth can they be accountable before God for your soul?) What a precious testimony this has been in seasons of doubt! I have often countered the lies of the enemy and of my sinful heart about my salvation by saying, "No! 417 other people, including my pastors, daily witness to my salvation! They see fruit in my life! They believe I am a Christian!" Second, formal membership provides a structure of accountability in a way that mere attendance cannot. You are consciously, intentionally placing yourself under the authority of your pastors, and humbly opening yourself up to be held accountable to a life worthy of the gospel. You're also taking on the responsibility of bearing the burdens of your brothers and sisters in the church and being willing to call them out when they sin as well.
Speaking of sin... Sin. I'm always surprised to read the "Dear Boundless" letters that deal with couples having sex or living together outside marriage -- the writers almost always characterize their behavior as "mistakes" or "slip-ups" or "crossing the line" or some other such convenient phrases; rarely does anyone write in and say, My boyfriend and I have been violating the standards of a holy God every Friday night for three months. We've also been dragging the name of Jesus through the mud by our behavior, and we'd like some advice on how to stop being an offense to the Gospel...
But that's just what sin is -- defiance against the rightful Ruler of the universe. Listen, I don't know if you know this, but God, as the Creator of all things, has the right to rule the universe as he wishes. You don't go to Iran, dance around on a picture of Muhammad in a town square in a bikini, and then think you're going to get away with it by calling it a "slip-up" when somebody throws your butt in jail. Sin is a serious, serious matter -- why would we look at our brothers and sisters in the church falling into persistent sin and look the other way? We should feel shame at the thought of standing idly by while those who bear the name of Christ deny him with their actions when we could do something about it!
And that's just what church discipline is, people. Church discipline, at heart, is the Body of Christ refusing to allow the beloved children of God continue in sin unchecked. It is a reminder to those who have ignored the Spirit's whispers that danger lies ahead.
99% of the time, church discipline does not involve "excommunication." Usually, the preaching of the Word, worship, the sacraments, and community life are the means the Lord uses to discipline his people. Occasionally, a brother or sister will have to call you out for a particular sin. Less often, someone will have to be confronted in love by the pastors if they continue to live in unrepentant sin. Usually, that person will repent in the course of one of those events. If not -- if that person continues to refuse reconciliation and ignore the pleas of his brothers and sisters, acting like he is not a believer -- then the church is to treat him in the way he is acting! The problem is, people see Paul's command to the Corinthian church to treat the adulterous man in their midst "as an unbeliever" and think that means they kicked him out. But doesn't your church welcome unbelievers? Don't you pray that unbelievers will show up? Don't you invite unbelievers to your services?
Church discipline is a beautiful ministry of the local body; I for one am blessed to be a part of a congregation that has the structures for church discipline in place -- it reminds me of both the grace and the judgment of God. I pray that I never have to be placed under formal discipline by my church, but I know that my fellowship with them is part of what ensures that I never will!