Hmmm, I thought this looked interesting, because it seemed kind of contradictory to me - but apparently the atheist church was founded mainly so marriages and other ceremonies could be done by an "ordained member of the clergy" that held to the same beliefs (or non-beliefs in this case.)
Here's a link:
First Church of Atheism It also says it is a place for people of like minds to gather and have discussions and fellowship.
I know that is a huge draw of most religions, the fellowship - the feeling that you are not alone, especially when tragedy strikes. Having my church behind me when I have had my extremely difficult problems with my oldest son has been a life-saver.
I can see that part being good for anyone - whether you believe in a higher power or not.