In the casual and open forums of small church gatherings, all teaching can be scrutinized by anyone who can read. Brothers and sisters who know and love each other are inclined to respectfully consider viewpoints that differ from theirs, and even if the group doesn’t reach a consensus, love, not doctrine, still binds them together. Any teaching by any person in the group, including elders/pastors/overseers, is subject to loving examination by anyone else, because the Teacher indwells every member (see 1 John 2:27). The built-in checks and balances of a biblical model help prevent it from becoming doctrinally derailed.
This is quite a contrast from the norm in modern institutional churches, where church doctrine is established from the start and not to be challenged. Consequently, bad doctrines endure indefinitely, and doctrine becomes the litmus test of acceptance. For this same reason, one point in a single sermon can result in the immediate exodus of dissenters, who all jump ship to temporarily find some “like-minded believers.” They know there is no sense in even talking to the pastor about their doctrinal disagreement. Even if he was persuaded to change his viewpoint, he would have to keep it hidden from many in the church as well as from those of higher rank within his denomination. Doctrinal differences within institutional churches produce pastors who are some of the most skilled politicians in the world, orators who speak in vague generalities and avoid anything that could result in controversy, leading everyone to think he is in their camp.