James wood, if you read frankensteins' on-topic exerts from albert's berlin writings:
He considered the quest to discover the unknow, the certainty that there was an unknown and his unveiling of the unknown HIS DEEPEST RELIGIOUS EXPERIENCE. in other words his religion was firmly rooted in reality (wirklichkeit) something to work (wirken) on/ at to make sure its real). He had goose pumbs when insights like e=mc2 stared him in the face while he worked on OTHER, related issues.like relativity. He had help by discussions with friends.
True spirituality for him was rooted in reality but reached out into the hidden reality that he was certain to be there. its divine.