A few theories I have that are out there somewhat but I think could make sense

It references William Blake, the Book of Revelation, and some of the 666 clues on the wall as well as
his paintings "The Great Red Dragon" (also the title of 6x07) and "fearful symmetry" to a strange cryptic extent.

I hope that Brett Partridge is Red John and not dead, I do not neccessarily believe anything Heller has said up until this point, because if it is Partridge the design is to shock people with his "resurrection".

What if the clue that will make sense to people later is the number of the beast 666 being painted on the wall? This could refer to the book of Revelation chapter 13: verse 3 " One of the heads of the beast seemed to have had a fatal wound, but the fatal wound had been healed. The whole world was astonished and followed the beast"

There are seven heads to "The Great Red Dragon" (Blake Painting and title of 6x02)
7 heads = 7 suspects
one head currently dead = 6 heads remaining
Heller has commented that other suspects on the list may be killed off as well, if 666 is not present 
at their deaths it may indicate that Partridge is "the beast", the resurrection a "fearful symmetry" of an seemingly omnipotent Christ figure.

Now how are they going to make it appear fool proof that Partridge is dead only to have him raise from the dead? For this let us go to another William Blake painting, the often quoted here, "A brace of Partridge". What is present in the painting, none but two seemingly identical partridges both connected together in this instance tied at the leg. Could Brett Partridge be a stage name, a given name , or a made up professional name by Brett Partridge to hide the fact that he is one of a pair of identical twins? could this be another example of fearful symmetry and also of "tyger tyger", forensically the DNA of the twins would be identical or near identical, as would be appearance obviously, at least enough for the forensics expert Partridge to easily make it appear that he is deceased. Obviously they could work together as red john "he is many" or one could be the "good twin" (now killed) and Brett that "bad twin" who is red john, this could stress the theme of duality and of the "Tyger" and the Lamb" present in Blake's Poem "Tyger Tyger" and also why as Partridge is dying he states this.

Could also explain why in intervals Heller insists "Red John killed Partridge and that Partridge is definetly dead", he never said Brett Partridge is dead, a twin could easily have the same last name meaning Brett Partidge (RJ) did in fact kill Partridge"

The clue other that the 666 in this instance could also be Lisbon remarking "Partridge!" as he falls on the ground. 

I think this would be a really different, unique and clever way to wrap this up

"clever!? I'll show you clever" - faking your own death in a way that forensically leaves no doubt you are dead?

thats pretty clever