Spinoza's God is interesting not because it's a competitor to the Christian God or Thor or whatever, but because it's a rarely-explored aspect of Einstein's belief system (and confusion) about the origins of, well, everything.
Questions of religion vs science plague proper scientists too, Einstein among them, and nobody really has a clear answer about how to proceed. It's the sort of inquiry that is itself perhaps a precursor to eventual discoveries -- what is now "What happened before the Big Bang? Did someone create it?" may one day, if we're lucky, be answered by something like "It depends. Which big bang are you talking about?" But there's no harm in asking the questions... just jumping to conclusions.
>>> Questions of religion vs science plague proper scientists too, Einstein among them
This is something you are making up, because in his own words Einstein clealry states opposite of your claim:
"I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it."
You can't just take one quote out of context and use it to paint Einstein as altogether disinterested in religion -- he wasn't.
To him, there was a difference between believing in Your Own Personal Jesus™, or some variation of Abraham's fickle, meddling god (as in Judaism, Christianity, Catholicism, Islam), vs contemplating religion as a social/moral force and a line of philosophical inquiry about the origins of structure and organization in the universe. The whole point of him mentioning "Spinoza's God" is to underscore that difference.
Einstein wrote about religion on more than one occasion, and his views weren't as straightforward as "religion is dumb, I don't think about it." Far from it; he recognized the universe as something inherently profound and beautiful and drew from it a philosophical sense of spirituality. No one is accusing him of being a Bible thumping Jesus lover, but he was definitely interested (on the side) on questions of spirituality, purpose, etc.
My own personal take is that Einstein recognized the limits of our understanding and drew peace and inspiration from the boundless complexity yet to be understood. He found it powerfully spiritual, but he did not attribute it to a "personal" god the same way a follower of the Abrahamic religions would. Nonetheless he was interested in these questions, even if he didn't have the answers and didn't believe the Christians did.
You wrote a lot of words to argue an unrelated point. Whether someone is interested in religion is not the same as whether they find truth in religion.
> Whether someone is interested in religion is not the same as whether they find truth in religion.
OK, I agree with that assessment. But I wasn't arguing that Einstein was deeply theistic. I was saying he and other scientists were deeply interested in religion -- not to the degree of a theologian, obviously, but interested nonetheless. I believe that to still be true.
Questions of religion vs science plague proper scientists too, Einstein among them, and nobody really has a clear answer about how to proceed. It's the sort of inquiry that is itself perhaps a precursor to eventual discoveries -- what is now "What happened before the Big Bang? Did someone create it?" may one day, if we're lucky, be answered by something like "It depends. Which big bang are you talking about?" But there's no harm in asking the questions... just jumping to conclusions.