Zack Beauchamp decouples his jewishness from belief in God:
We find value in the traditions we participate in, a value that’s independent of whether we believe the same things as the people who have participated in them in the past. The fact that my parents, and (one pair) of grandparents, and their parents, have all been Jews matters to me. Being Jewish in this sense is a feeling, whereas belief in God is a belief about the world, one that must (like all beliefs) be subjected to rational assessment. But the fact that God can’t pass the intellectual smell test doesn’t say a thing about whether I can find value in participating in the traditions that shape my cultural heritage. I simply do, in an almost pre-rational sense.
On a related note, William Deresiewicz tracks how his atheism has evolved:
I no longer divide the world between believers and nonbelievers. I divide it between fundamentalists of both kinds and (for lack of a better word) liberals of both kinds. Liberal Catholics, Reconstructionist Jews, various kinds of mainline Protestants: people who understand religion the way that I understand art, as a source of spiritual wisdom and moral guidance, not literal truths about the physical world.
The Dish 