Because they have to be in order to function.
By "religious," I mean that they believe in things not supported by evidence or science.
In pondering what might be the larger themes in the gay marriage wars, the evangelism of the new atheists and even the campus trigger warning craze, I keep coming back to the same thought: these are religious wars, not political ones. I'm becoming convinced that politics follows culture which itself is founded on a dominant religious belief.
The reason I think everyone is religious is simple. Chemistry does not allow for the self. I know this is an old argument of mine, but it keeps jumping out at me in the context of finding the bigger themes. Here is the argument again in case you missed it before.
From a Gonzaga website, Gonzaga itself being a Jesuit university and as such, like the Jesuits, could be considered either Catholic or secular depending on which fad the Jesuits are following today, offers up this web page for one of their chemistry classes containing the diagram below.
This is an energy state diagram for a chemical reaction. The reaction is well-understood. Subject to the caveats of statistical chemistry, this is the way it always behaves. The same reactions are constantly occurring in your body, governed by similar rules. "You" have nothing to do with them. They simply happen.
There is no evidence for "you." There is no science that supports free will. There is nothing in anything we understand, and what we understand increases every day, that suggests anything other than nihilism. I've heard plenty of counter-arguments in the comments of this blog, but none of them undermine the diagram above and the diagram above and ones just like it are the basis for everything in the Universe.
If you argue, if you cajole, if you hold "beliefs," if you take positions, if you talk about "individuals" or "people," you are religious because you believe in things that are not supported by evidence or science. Everyone, everywhere must be religious in order to function. You have to believe that "you" exist and "you" are making decisions, despite the evidence to the contrary.
Secularists are not devoid of religion, they are devoid of a coherent cosmology. That is, they wave their hands about when discussing Creation, the meaning of life, the purpose of existence and so forth. They're religious, but in a primitive sense like the Apaches. The Apaches had a vague creation myth which secularists replace with the Multiverse, repetitive Big Bangs, or whatever hip creation myth they heard on NPR last week. It doesn't have much of an effect on them other than to release them to do whatever they want, which is the key to the post-modernist belief system.
That's the key. Attacks on Christianity or Islam or Judaism are not attacks on religion itself because we are all religious. They are attacks on particular cosmology by people who want to replace it with their own, their own being essentially a retreat back in time to something closer to the creation myths of the most primitive humans.
The Great Spirit forming the world out of the foam at the bottom of her tub after washing her hair isn't substantially different from the sparkly unicorns of the Multiverse. The important thing is to get all that out of the way so you can get on with the important tasks of robbing and killing the Navajo or worshiping your crotch, whichever tickles your fancy.