Secularism’s philosophical roots may run as deep as the writings of the Hebrew Bible, Paul and Augustine. Yet for our purposes we should understand modern Secularism as a development whose major architects were Martin Luther, John Locke, Thomas Jefferson and James Madison.
A blog post is not the proper place to develop such an argument and I have, fortuitously, written an entire book about this subject. But to put it as pithily as possible, let me note that each of these (religious) men was deeply skeptical of any sort of contact between the State and the Church.
A secularist, then, dwells not in the atheist realm of theology or anti-theology, but in the domain of politics. A secularist asks: how can we get this here Church/Mosque/Synagogue to be treated justly by government? How can we make sure that this here Church/Mosque/ Synagogue doesn’t take over the government? How can we keep this religious group from trying to exterminate that one? How can we assure religious freedom and freedom from religion for all? How can we make it so that Christians and Atheists, Muslims and Agnostics live in peace and order?
You see? You see? The man's sayin' what I've been sayin'! But I also agree with the other theme here: balance. Balance is the key. But it's also a more conservative principle than progressivism. Balance accepts the existence of whatever sort of "negative" principle you define yourself against without seeking to obliterate it.
In this context, that means I'm only interested in making sure that my atheism is legally protected. I have no desire to convince other people to share it with me in the belief that a world full of atheists would necessarily be a better, more rational one. Would the world be "better" without religion? In some ways, probably; but it also verges on being an incoherent question, since we have no perspective from which to judge, and no way to anticipate the ripple effect that such a fundamental change in the world would create. Crusaders for a cause tend to convince themselves that such changes are a simple matter of adding this or subtracting that, while the countless variables that they overlook in their tunnel vision continue to multiply exponentially.
And though I give mainstream Christians a hard time for their intellectual squishiness, it's also true that a Christian who accepts the idea of different religions all being valid paths to more or less the same goal has, as far as I'm concerned, become thoroughly secularized. If they're willing to relinquish the very exclusivity that defines their faith, the belief that there was one-and-only-one son of God, and he brought the one-and-only-one path to salvation, well, then, by all means, they can continue to go through the motions with their churches and holidays and empty rituals! How greedy would I have to be to want to take even that from them?