Churches are meant to be places of love, peace and harmony, where God is praised and Christ is present by his Spirit.
Usually they are. Sometimes, though, something like civil war can break out, and far from looking like a colony of heaven, a congregation can look like an outpost of hell.
One reason for this is that people are people. We are fallen and flawed, and we don't always live up to our high professions. So the church can become an arena in which people seek influence and control, where they attempt to dominate others and get their own way to fulfil the needs of a warped or broken personality. It may be dressed up in spiritual language, but there's nothing godly about it. Such people can damage a church profoundly, sometimes over many years, as their own agenda is served in the name of the gospel.
Another reason is that there are sometimes big issues at stake. Where people have deep convictions about the Bible and the gospel, passions run high. It's easy to see those who take a different view as the enemy, to be resisted with every fibre of one's being. Any idea that they're on the same side, that they too love God and are fellow believers, is left behind.
Where churches fall out, for either of these reasons, it takes real courage and persistence to counter it. Those who stand up to harmful people can find themselves frozen out, their motives are questioned and they can even face expulsion. Those who fight their corner even when they might be in a minority, who are the ones who speaks up at church meetings, risk being seen as disloyal or obstructive. Often it's easier to walk away.
Sometimes, when a church is too far gone in wrongdoing, that might be the right thing to do. But the presumption should always be that we stay put for as long as we can. We won't necessarily get our own way, but it's vitally important that the church has a witness to the reconciling power of God. The Apostle Paul in 1 Corinthians 12 speaks of the church as a body with many parts. Sometimes the body gets ill, and needs healing. Prayerful, loving people, who act with integrity and keep their eyes focused on Christ, are the ones God uses to bring that healing.