Another example: I don't know if Eric Raymond would self-describe as atheist, but he is a neopagan with, as far as I can tell, a naturalistic worldview.

Edit -- a key quote:

One great virtue of this dual explanation is that it removes the need for what William James, in his remarkable "The Varieties of Religious Experience", called the "objective correlative". By identifying the Gods with shared features of our psychological and inter-subjective experience, but being willing to dance with them on their own terms in the ritual circle, we can explain religious experience in respectful and non-reductive ways without making any anti-rational commitments about history or cosmology. Scientific method cannot ultimately be reconciled with religious faith, but it can get along with experiential mysticism just fine.