In episode 29, I know that the people that Cooper believes to be Laura, Maddie, Leland, etc. are just dopplegangers that have been put there to instill fear in him. But my question is, does your soul need to have passed through the lodge in order for your doppleganger to be there? For example, could Audrey or Shelley or Bobby have dopplegangers in the Black Lodge even though they have never passed through it?

I think so

i dont think so

Hawk:

"Legend says that every spirit must pass through there on the way to perfection.

There, you will meet your own shadow self."

I assume that goes for anyone confronting the Black Lodge.

Hawk refers to the Dweller on the Threshold and the Bardo Worlds, taken and modified by Theosophy from Buddhism. Everyone who dies, which is everyone, has to pass through these levels (read The Tibetan Book of the Dead, which Cooper quotes as he ushers Leland "into the light.")

So it's likely everyone's shadow self is always there, waiting.  

Thanks for the clarification guys. I'm kind of leaning more towards 12rainbow's theory though. Eventually, everyone will pass through the Black Lodge, and if there is no real sense of time in the Lodge, (i.e Cooper and Annie communicating with Laura before she died), then everyone would be there right? That's what I'm starting to think.

i was kind of thinking that the shadow self is made, generated, during the firewalk. it doesnt "exist"(which is a highly speculative word here) in the lodge until one gets to the point of meeting it.