Well, it isn’t just Christianity, but any theism, and even broader, any supernaturalism. But this post concerns the narrower question: what drives my formidable and publically expressed anti-theism. I have been asked about my “attacks” on religion by persons who know that in most ways I’m not a judgmental person. They wonder why the discrepancy. Why don’t I just leave people to their beliefs in peace. Why am I so intolerant of people’s sincerely held religious ideas? Am I offended by “Merry Christmas,” a Christian cross, a nativity scene, or that someone is praying for me? I think these are reasonable questions.

Truth is, my reaction to religion is of two quite separate sorts, only one of which gets a vehement reaction, while the other does not.

Here’s the mild one: I enjoy intellectual discussions of different belief systems, specific beliefs, and their origins. It is interesting to me, for example, when early Christians decided that a trinity would be orthodox and its absence would be unorthodox or even heretical. Or what led early Christians to incorporate Mary (mother of Jesus) into a heavenly figure. How did the Sunnis and Shia divide up Islam orthodoxy? What stages developed out of Siddhartha’s original Buddhism into the several branches existing today?

What is the evidence for I, II, and III Isaiah? Why is the Catholic Church so married, as it were, to an unmarried priesthood? Why did John Spong, liberal Episcopalian bishop, humorously say his atheist detractors accuse him of putting lipstick on a corpse? Which book(s) of the Old Testament seem not to have been written by Hebrew authors? Why are the “gospels” first in the New Testament, rather than the epistles which were written earlier? What gave rise to the competing Christologies of the first couple of centuries CE?How recently have European countries put heretics to death? How ethical are theists versus atheists and other non-theists? The list is endless and, I think, intriguing. These issues of history and theology engender in me a non-judgmental, calm, and friendly frame of mind.

Consequently, I am perfectly undisturbed by a cross or crèche on private property, by a cheery Merry Christmas, or a well-intended prayer. I am in no way offended by them. Of course, even if I were, I don’t have a right not to be offended. Moreover, I am frequently impressed by the humanitarian and charitable works of persons acting, at least in part, out of religious conviction. Theirs is a laudable gift to humanity, for whether the motivating religion is true or not, good will is to be celebrated and appreciated.

But there are religious matters that stimulate another reaction entirely rather than just an unruffled intellectual interest. For me, these issues of the second type are the only ones worth writing a blog about and the only ones that I feel evangelical about. So while the product of the first type of interest is fascination, that of the second is zeal.

A bit about the zealous one: My dander gets up when adherents to a religion seek to control others including, of course, me. Even then, I stand foursquare in favor of their religious liberty, that is, their right to believe what they will, practice their belief, and try to convince others—including me—if they wish. It is important, however, that their freedom is not to be construed as the right to tell others what to do, regardless of who is in the majority. Christians can erect a billboard extolling Jesus and I can do so saying the whole thing is a myth. I should defend their right to do that and they should defend mine, no matter how much each of us thinks the other is dead wrong. But that mutual commitment depends on our truly believing what our Constitution and—I would hope—our consciences have to say about religious liberty.

I become zealous when I hear of public school employees teaching Christianity or giving it special favor, as happens thousands of times daily in America. I’ve the same reaction when a city council prays at meetings, police cars have religious messages painted on, a public park has a religious display, or any other situation in which government decides what are proper religious positions. This blog has numerous posts addressing the abundance of Christian theocratic arrogance of this sort. (Two recent ones of probably more than a dozen are “Democrats vs. theocrats,” Jan. 30, 2016; and “Religion in the public square,” Oct. 20, 2015.) Any time public servants take advantage of their public role to espouse their religions positions, they are speaking as the government—patently unconstitutional. We all remember Kentucky county clerk Kim Davis, who, in popular perception, unilaterally disregarded the law of the land because she thought she had the religious liberty to do so. As an individual, Ms. Davis, does; but as a county clerk does not. I find that widespread type of bullying behavior infuriating.

Worse, on TV we were treated to the shameful spectacle of presidential candidates Mike Huckabee and Ted Cruz coming to the defense of her proposition that the clerk’s religion-based distaste of LGBT lives justified not giving them what the law prescribed. Cruz and Huckabee, like the earliest European settlers of North America who came not for the ideal of religious liberty as is claimed, but for their own religious liberty over others. The current spate of misnamed “religious freedom” laws are, in fact, governmental preferences for certain fundamentalist Christians, excusing them from a legal requirement binding on everyone else, one that would not—despite pious pleas—deprive them of legitimate religious liberty.

Religion is rank supernaturalism, makes claims not backed by evidence and often in contradiction to evidence, it can justifiably be treated as just another of the bizarre and evidence-free beliefs of humanity. It can even offer some amount of comfort if you don’t look too closely. So although it provides fun discussion and occasionally contributes fodder for thoughtful consideration, more than anything else it simply demonstrates human gullibility.

Yet when armed with pious arrogance, religious adherents set out—as Christians and Muslims regularly do—to tell others what to do, to appropriate governmental power to promote their aims, to declare hegemony for their flawed moral code, and to claim entitlement to advantageous treatment, I am not just offended; that is far too mild a term. I am furious.

And that is why one aspect of religion to me is of anthropological interest. Yet the other aspect is sufficiently inhumane, counterfactual, and bullying to call for calculated opposition. In the presence of the first, I am calm, mellow, and playfully nerdy. In the presence of the second, I am vigorously belligerent, and yes, vehement.

But always to be remembered: It is no diminishment of my opposition to religion to argue with equivalent emphasis that respect for individuals of whatever beliefs is not just a nicety, but a moral obligation integral to humanist ethics. The mantra that has long worked for me is, “Though I do not respect your religion, I do respect you.”