Einstein was an atheist for most of his life (or a type of person who is "neutral" about religion, or can't prove god exists and can't prove god exists) up to a point in his science career when he realized that the universe (he looked at religion in a cosmic sense) could not exist without some Hierarchy or order governing the things existant in it. That's when he came to the conclusion that god did exist, or at least some sort of supernatural being or system.