Is the Society of Friends/Quakers creedless and non-theistic, or is it explicitly theistic?
They are theistic. I am unsure of the creed matter. My ancestors were Quakers, and I have read about their theology a bit, so I do know they are definitely theistic. Knowing a bit about their beliefs, in particular the idea that the light of God exists in all of us and that the Holy Spirits speaks to us all, I am inclined to say they probably don’t have a set creed. But I could be wrong on that. Edit: Here you go. Unlike many other groups that emerged within Christianity, the Religious Society of Friends has tended away from creeds, and in modern times away from hierarchical structure.[3] The various branches have widely divergent beliefs and practices, but the central concept to many Friends is the “Inner Light”. Accordingly, individual Quakers may develop individual religious beliefs arising from their personal conscience and revelation coming from “God within”; further, Quakers feel compelled to live by such individual religious beliefs and inner revelations.