Just to interject another line of thought into this debate.
It seems to me that not long ago many people just attended church because people just attended church. It was the thing to do, and although there were many people who knew what they believed and why, there were also many who didn't give whatever faith they had a lot of consideration.
Atheism has forced Christians, and those who are considering Christianity, to determine just what it is they do believe. In western society people in general do not go to church because it is the socially correct thing to do. This I believe is very positive for the Christian church and to a lesser degree other faiths as well.
Atheism became a force at the time of the French revolution in response a corrupt political regime put in place by the church in France. Any time the church actually gains political power there will be those who become active in the church not because of their faith but because it is the path to power.
Atheism has, as a result, been largely responsible for seeing that the church does not gain political control which helps keep the church on track by keeping those seeking political power in government out.
As I said, I believe that Atheism had a cleansing affect on the Christian church and has been a positive for our society.
Everybody is entitled to my opinion.