I think his theory holds the presumption that all healthy types would believe in God, health would mean becoming a theist if you're not one, and that 10 you'll naturally be inclined in believing,(free of doubt maybe) something that E10 is gifted with and all other types have to work to get there in a sense.
In other words if I understood it correctly health/integration=theism, unhealthy/disintegration=atheism or agnosticism
Also even if we don't believe in a higher entity of any sort, it's still a question everyone of us has asked himself, a question immanent to human nature and the way we answer it determines in a way our existence. Although I have to agree: the particular fear of not serving God doesn't fall into that category because though it may be that questioning his existence might fit into that category, the fear of not serving God is exclusive to religious individuals, so maybe E10 fear can be that God doesn't exist.