I think there's a post somewhere on this site that makes the reasonable point that "is atheism a religion?" is not an interesting question

Both Religion's Claim to be Non-Disprovable and Beyond the Reach of God should be useful. If you show that the hypothesis "God(s) do exist" is most likely untrue then, correct me if I am wrong, the opposite hypothesis "God(s) do NOT exist" is most likely true.

As long as you don't use the word "faith" in the first hypothesis, then I hardly see how atheism needs faith to back it up.