A new letter has surfaced from Einstein which would appear to once and for all clarify his views on theism. Writing to Eric Gutkind (Jan 3rd 1954), Einstein states:
The word god is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish. No interpretation no matter how subtle can (for me) change this.
Later in the letter he describes religions as "an incarnation of the most childish superstitions." So once again, I think we can classify Einstein’s "God" as the God of Spinoza as opposed to the "childish" views of classical theism.