If you're a militant atheist and want to believe you are destined to become a pile of dirt (that is the final natural conclusion)more power to you. However, our founding fathers were Christian and their faith is what shaped our Constitution and other distinctly American documents. We believe that the Creator gave you the same unalienable rights even the freedom not to believe in the Creator.
Those documents protect you as well. So do not try to shut down religion in the public square unless you're willing to give up YOUR freedoms.