As an atheist I am pretty mild when it comes to religion in theory. I don't care if you believe in fairies and leprechauns. We've been religious ever since we were painting cave walls. We worshipped what we ate. Now however we worship what eats us - demon sky gods and other monstrosities.
I only get aggressive when said religion tries to impose itself in the public arena such as school prayers or imposing their sacred texts on the public. This, the US, is not a Christian nation nor a Buddhist or Hindu or atheist nation. It is a nation for any, every and no religion. Secularism - religious neutrality - is the proper stance for a nation state.