I thought their doctrine was more simple when they did not have the "other sheep" class. Apparently not. I wonder how they managed to attract so many people to a doctrine like that, with classes of people being saved.
I asked because I found a book in the online congress library, a book published in 1880's, that talkes about an earthly kingdom of God. And I thought, since this was an idea preached during those times, maybe they preaches something similar, too.
Here is a link to that old book. It is very readable.