The religious love to claim Einstein as their own. They do so because the misinterpret his remarks referring to nature as God, in a Spinoza-esque way. This recently-found letter of his should (hopefully) put the issue to rest.
Einstein was, by most accepted definitions, an atheist.
The word god is for me nothing more than the expression and product of human weakness, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish.
For me the Jewish religion like all others is an incarnation of the most childish superstitions.