I know this isnt the answer you were looking for but I need to ask this. If you were raised without religion in your life how have you determined that you dont believe in God? How many different religions have you looked into? Are there definite reasons that you decided that you dont believe in God? Any "non-believer" that I have known has a very definite reason why they dont believe in God. To make an informed decision about any subject you need to investigate both sides.
I hope you find the answer you are searching for and you feel good about the decision you make about Scouts. It is a wonderful program and I am sure that you will be missed if you quit.