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 

I have a theory
I believe kirkland is not red john
I either believe he wants rj for personal reasons
Or for something else. Also I believe the list is fake/real pj would not leave the list in his room rj is to important to him for that. My theory is rj is bret stiles and brett partridge the whole house scene s6 ep1 it takes 2 to pull off what happened there I believe they are father and son the whole barn episode was done by stiles then partridge took over stiles has the money all the friends aka visualize which to me explains he is many. Partridge does all the killings red john makes no mistakes crime scene investigator its a father and son team brett and bret why do you think stiles knows so much about rj its just a theory I would be glad to hear from you guys on what you think

Brett Partridge is Red John! The last scene almost confirms this suspicion. One should note that the way Liz is nabbed, it's clearly like someone pulls her legs from below. Now it couldn't have been anyone else but Brett who as we know has fallen down and therefore, is the best person to grab her from below by her legs!

Probably nothing, but when the team go to get Kristina Frye from where RJ has her in S3, their is a paint brush on a stool or something, next to a bucket and lighting equipment. Move forward to last episode, when they go to the desert crime scene with Brett Partridge. Exact same type of paint brush is in one of the shots haha. 

Since the beginning I always believed that BP was RJ, and I'm sure you're all familiar with all of the clues that lead to him.

What we all need to realize, is that The Mentalist is NEVER obvious. When I found that BP was on PJ's list, I started doubting myself. Why would Bruno Heller PLACE the answer in our hands? Why would he take away every element of surprise? Though, when BP was 'killed', my faith in my theory was restored. How else would you surprise the audience? Make the 'dead' guy the killer all along. We won't see him for the rest of the series, and at the last episode we will find that he's RJ.

Let's say I'm wrong. If I do happen to be wrong, (which doesn't happen often), I can assure you that it will NOT be one of the other 6 on the list. There would be no element of surprise, no shock, nothing. If it's not Brett Partidge, it will have to be one of the main characters. That is Lisbon. Rigsby, Van Pelt, or Cho. I think it would be really shocking and thrilling if it was one of the main characters, and it would make for good television. If anyone is Red John out of all of the prinicipal characters, I think it would be Cho.

I DON'T THINK it's PARTRIDGE.  I think he's dead.  But this website won't let me pick the one I really accuse.  
Anyway, could Jane's FAKE list of 7 suspects hold symbolism for the 7 deadly sins?  I think that points to these characters all having a weakness that will lead to their undoing, and the proving that they're not RJ. 

 
1.  Sheriff McAllister:  SLOTH.  He's a REAL DONUT SHOP COP.  About 20 steps behind everyone, including himself.

2.  Ray Haffner:  GREED.  Money talks but RH is seriously motivated by money as his main interest and goal.

3.  Gale Bertram:  GLUTTONY.  At first, I thought him GREED -- because of GB's poker habit but I realize he has more the desire to win than to just have money.  Another definition is "the ability to withstand," as in glutton for punishment, which GB certainly is, and also an excessive "love of power," or at least for GB, a love of looking good.

4.  Reede Smith:  I thought Gluttony because of his obvious physical appearance but his true point of his nature is: WRATH.  The guy has serious anger management issues.

5.  Brett Partridge: LUST: or blood lust [ghoul!!]

6.  Bob Kirkland: ENVY: he truly seems in direct competition with Jane and the CBI, but why?  We don't know yet.

7.  Brett Stiles: PRIDE:  the biggest ego of all -- I think he could have a connection to RJ, but isn't actually him.  [Perhaps a father or father figure maybe]

For me, there are only 2 possibilities:

1- Partridge isn't dead, he is Red John and it was just a trick to caught Teresa easily.
2- Partridge is dead and my number two, Gale Bertram is Red John. If i remember correct, Teresa called him in one Episode as " a clown". This could be the explanation why the Killer painted a Clown-Smiley on her face.

Furthermore:  in my opinion, the List of final 7 suspects is correct. It has to be...