So in FWWM we can see the process of physical and moral destruction of Laura. For me, it looks similar to the last temptations of Christ. She had to die to not to allow the evil forces dominate, so Jesus did. For her the last 7 days are like the trials for Christ before his death and resurection.
In The Return we can see the Giant sends the orb with her to Earth. As The Giant is the host of the White Lodge< so he is the God of the Twin Peaks universe. So Laura is daughter of God, who was sent to protect the humanity from Lucifer(BOB and Judy) and died to fullfill her destiny, like Jesus died for humanity's sins?
In the last episode Laura has been brought back by The Giant(God) and Cooper(let's call him Archangel Michael for example) in order to destroy an Evil for good? Much like the Second Coming - An ultimate destruction of evil forces and bringing the Peace and Heaven to Earth. So Laura has brought back an Apocalypse to the world of Twin Peaks.
Sorry for my English. I thought it might be interesting. Watching FWWM again right now=)
I've mentioned on here before about the sending of the Laura orb to earth being reminiscent of Christ being sent to earth to be sacrificed essentially. Never tied in the suffering of Laura in FWWM to the trials of Christ before death but I can see where you're coming from.
It's funny, for all the (justifiable) talk of Native American and Eastern spirituality that runs through Lynch's work, he does seem to have Christian interests too. I'm thinking the bible quote that unlocked the meaning of Eraserhead for him. Also, I think it was the Lynch 2 documentary, but I'm sure he talks about reading the bible then and starts talking about a bible story in relation to Inland Empire. Or am I imagining that?