That depends on your definition of the word “god”. Einstein certainly wasn’t an Abrahamist, he was a pantheist. He believed the entire universe was comprised by a divine whole.

You shouldn’t use “god” as a proper noun. No one being owns the concept of being a god. You’re just legitimising Abrahamism, you’re not helping the atheist cause. Helping Abrahamists erase polytheism doesn’t lead to more atheism, it leads to more Abrahamists.