Hmmm...

Whispered to me across the dining table by an American Bishop

[One of the brilliant,devout and orthodox ones so that reduces your guesses to a handful]

"What's the difference between a liturgist and God ?"

"God doesn't think He's a liturgist !"

"How many Liturgists does it take to Screw in a lightbulb ?"

"Just One, They hold the lightbulb and the Universe revolves round them...."

"What's the difference between a liturgist and a broken clock ?"

"A broken clock is sometimes right"

a few more from other sources :

"What's the difference between a terrorist and a Liturgist ?"

"You can negotiate with a terrorist!"

"The difference between an Atheist and a Liturgist?"

"Atheists admit they don't believe in God and some of them know Latin"