Maybe you didn't notice that he asked a question TO atheists?
Yes, I did notice that question in the middle of the OP.
Jam, I appreciate your OP. It takes a lot of courage to make a thread like this. I've known people who were not completely convinced either way about God's reality or non reality who decide to address their prayers to the Great Spirit. My father's maternal grandfather was full blooded native American. Dad always prayed to the Great Spirit. He was not agnostic, it's just what he was more comfortable with. When I left the org., I prayed to the Great Spirit. There are times I still address my prayers that way. I am not a doubter, but being a universalist, I don't feel a need to address God in any certain way.