Jesus, Save me from your followers

I had dinner with my Girlfriend's friends last night. We went to one of the most popular Korean restaurant in Sydney called Seoul-Ria to have lovely Korean food.
We went with 4 other koreans and 1 Isreali. We had a good time eating the food, my fave KimChi and Gal Bi (Korean BBQ Pork Ribs).
Anyway one of her friends called Charlie, a Korean, was wearing this Mambo tee with Jesus in front, below it reads "Jesus, Save me from your followers. Mambo 19:18". I thought that is a really funny shirt considering that my GF is Catholic and 2 other koreans were Presbyterians.
So we went back to their apartment and we happen to talk about the shirt. The guy has no idea what it meant! And he was thinking of wearing it to Church on Sunday!!!!!
I was laughing so loudly (after what he said was translate to me in English by my GF) and they were all looking at me.... I did not think they appreciate my laughter. :P
It was funny, of course, it isn't exactly funny when your girlfriend is a catholic and you are anything but christian. Thats the dilemma. Anyway, come what may.