http://en.wikipedia.org/wiki/Michael_Servetus
John Calvin was the chief instigator in the execution of Servetus for challenging his authority. After burning Servetus at the stake, Calvin wrote:

Whoever shall maintain that wrong is done to heretics and blasphemers in punishing them makes himself an accomplice in their crime and guilty as they are. There is no question here of man’s authority; it is God who speaks, and clear it is what law he will have kept in the church, even to the end of the world. Wherefore does he demand of us a so extreme severity, if not to show us that due honor is not paid him, so long as we set not his service above every human consideration, so that we spare not kin, nor blood of any, and forget all humanity when the matter is to combat for His glory.

Marshall, John (2006). John Locke, Toleration and Early Enlightenment Culture. Cambridge Studies in Early Modern British History. New York: Cambridge University Press. p. 325. ISBN 0-521-65114-X. That no such doctrine was ever a part of the teachings of Christ’s ministry or the early Christian church has caused no end of debate as to the real intentions of those who tortured and killed those whose views differed from those of the ecclesiastical authorities at the time.
Primary: Calvin, Defensio orhodoxae fidei (1554), 46-7; Allen, Political Thought, 86-7

So, to that great Christian theologian, reformer, and leader [at least to some], I am either an idiot, too dumb to know better, or a simple sinner, too self-centered and short sighted to care, or I must be an atheist.

I reject all of that. (Besides, it reminds me too much of Marx, Lenin, and Mao and their allegiance to communism.) I’m a Christian. I just think a god who needs men to defend him, even kill for him, is simply no god at all. My God is bigger than that. My God can handle my failings, and yours too, and He doesn’t accept it as good if either of us judges the other over it. The scripture teaches to judge fruit, not men. Burning someone at the stake for holding an unusual trinitarian view and for renouncing infant-baptism is not good fruit. John Calvin seems to have had more rotten fruit than good.

For some, I think violence against others with regard to belief stems from power and authority problems (“Power corrupts…”), but for most, I believe it stems from fear. We Christians are commanded to walk in love, which casts out fear, and in faith, which is opposed to fear. This would seem to apply to other areas of life, especially to politics.