I wrote previously that if you accept political speechifying that you agree with in the name of God, then you have to accept it when such phony 'prophecy' is contrary to your own political views. Jonathan Marlowe responded:
However, it would at least be the right kind of discussion to have.
In other words, arguments over faithful biblical interpretation are more interesting and important than the Enlightenment's argument about the separation of faith and politics.
Let's have arguments over what is biblical and what is not - rather than what is political and what is private.
I tend to be generous about the politics of other Christians. That is, I don't think that a person ceases to be a faithful Christian if s/he has political opinions that are liberal or conservative.
Why? Well, in my life I've been all over the political spectrum. There aren't many subjects that I haven't changed my mind on over the years. And because I've had a lot of political movement in my own views, I don't think that I have reached my final position on what is a correct understanding of public policy. Nor am I inclined to think that someone is necessarily evil because they hold political views other than my own. If I did, I'd have to condemn myself. For example, I once supported campaign finance reform (e.g. McCain-Feingold). Eventually I came to my senses, but I don't think that I was wicked or damned to Hell because I once thought that McCain-Feingold was a pretty good idea. People can disagree on political issues and still be faithful believers in Christ.
I say this because although the Bible has an enormous amount of information about who God is, and a lot to say on ethics, it has virtually nothing to say on public policy. Nor, I would add, does it have much to say on auto mechanics, but that doesn't make it a diminished book. The Bible, contrary to the fantasies of Jim Winkler, doesn't say which Senate Resolutions should be passed and which should be voted down. God left it up to us how to govern our nation and replace our motor mounts.
So it is completely appropriate for Christians to espouse a wide variety of public policy positions. But it is inappropriate for Christians to say "God wants us to support this bill to ban gay marriage/confiscate handguns/mandate prayer in schools/fund Social Security." It's inappropriate because the Bible never says these things.
And therefore it is wholly improper for the institutional Church to state that one position on a public policy issue is the only legitimate view for Christians to hold, or for pastors to give political speeches from the pulpit, as though they were reading the Word of God. Let individual Christians express any political view that they wish, but let them not claim that they have the same authority as the actual prophets of the Bible, such as Isaiah, Jeremiah, and Elijah.
UPDATE: Henry Neufeld has an excellent response to this post. Go read it.