I'm visiting family in Pennsylvania and I remember some of the things I said and did my first visit here and I decided I was a jerk. Oh, I was a jerk for all the "right" reasons. Heck, I had almost all the same values I have now. But I had no experience in actually being a radical Christian.
Red letter Christians have just as much possibility to be a jerk as other people, especially in the fanatical variety. Whenever one is a fanatic of any type (whether Christian or atheist, liberal or conservative, for peace or for war) the greatest danger is the refusal to allow others to live as they are going to live. Fanatics just can't see why anyone would have a different point of view. "If you hold to these presuppositions, then you must come to this conclusion." And so you expect that if anyone else belongs to your general group (Christian or Republican or peacemonger or skeptic or whatever) then everyone in that group should be the same type of ideology you are because that is simply logical.
We need to realize, fanatics are the way we are because we hold to a rare or unique point of view. Others won't hold to our point of view. We have the right to hold our point of view, but we cannot insist that others must convert to our logic. There are plenty of people who come to different conclusions and just because we hold one point of view, it doesn't mean anyone else must. We all are given the freedom of choice, and we must accept others' freedom to make different choices. Maybe right, maybe wrong, but we are all responsible to ourselves and our gods to follow consistently our own ideology.
Also, just because we have followed a certain line of logic, it doesn't mean that it is better than other people's point of view. I can show that a Christian shouldn't support war. But if I insist on this point of view for all Christians, I am missing the fact that there are a lot of different kinds of Christians and, in the whole realm of Christendom, I am in the minority in my presuppositions as to what makes the best kind of Christianity. Thus, others can be perfectly good Christians and hold to a different point of view.
I didn't see this when I was twenty seven. I hope that I'm more accepting to different points of view, or at least more ready to allow God do the judging and not me.