Go up to the concession counter and say: “I’d like a large popcorn, a box of red vines, some Body of Christ, and a large Diet Dr. Pepper, please.”
When the hammer comes down, yell “Ow! I broke a nail!”
Though it may be somewhat in the spirit of the movie, do NOT say “Ayleyn enuun Oorqey?” .
Do NOT bring a kazoo to play along with the interesting instruments of the period and place.
Don’t plan to dress as a penis and vagina to attend the movie. See Fark comments here.
[Peterman voice]
I can’t take my eyes off the passion!
[/Peterman voice]
Oh yeah.
Don’t loudly refer to the first two rows as the “splash zone.”
(I really did that one and ended up getting some very odd looks from other people in the theater)
When they’re taking Christ off the cross don’t say, “There’s a dead messiah on the landing!”
According to one of the Gospels, I think Luke, Jesus healed to man who had his ear cut off by Peter. Maybe Jesus did it on the sly when the camara was on someone else.
When they show Jesus, arms spread out on the cross, do not break into this song: I believe I can flyyyyy…I believe I can touch the skyyyyyy…
Don’t go into the, “dead man walking,” routine from The Green Mile.
When leaving the theater, don’t complain about how the studio felt compelled to give the movie a happy ending to sell more tickets.
Probably shouldn´t have posted on this topic, given my nick.
Don’t yell out “I hear he dies in the end” during the opening credits.
Don’t yell out “Floggin’s too good for 'im. Scourgin’s too good for 'im. Crucifyin’s too good for 'im” as the movie progresses.
Start singing Depeche Mode’s “Personal Jesus” at the top of your lungs.
alternatively, do not say “I once caught a fish THIIIIIIIIS big!”
when the disciples are entering Jesus’s Tomb, (i haven’t seen the movie so i’m guessing here) and call out Jesus’s name, do not answer in a deep, guttural voice “There is no Jesus, only ZUUL”
When Jesus arises from the grave, do not remark in a Proffesor Farnsworth-esque voice “Holy Zombie Jesus!”
hey, any film can be improved thru strategic MSTing 
When Jesus is being beaten and abused do not yell out any of the following;
“I’ve 'ad worse”
“Tis but a scratch”
“Have at you!”
“It’s just a flesh wound”
“Right, i’ll do you for that!”
“I’m Invincible!”
and Especially do not say the following after the cross has been raised;
“Oh i see, runnin’ away eh?, you yellow Bastards, come back here and take what’s coming to you, i’ll bite your legs off!”
<thunder clouds rumble>
oh, nothing, nothing…
Yell, " Make it stop, Mommy, MAKE IT STOP!!!)
When the Virgin Mary is having her last words with Jesus on the cross, do not shout, “Mom, could you go get a stepladder and some pliers? Is that asking too much, Mom?”
WHOOOOSH!
During the flashback sequence where we see Jesus as a carpenter, don’t say “Hey, Jesus designs IKEA tables!”
Which is really what I thought when I saw that scene.