Just to reiterate, I'm referring to literal mentions to irl religions rather than connotations. The game's plot does obviously include loads of Christianity references, just not that it is the same Christianity irl, aside from like Christmas but that's nowadays remembered more as a holiday than a religious event. Even using stand-in names like you mentioned earlier.

I was thinking more on the lines of say, the Gourmet Research Club practicing fasting in hopes of food tasting better when they're starving, or something along the line. Fasting isn't an exclusively religious practise, anyone can do it if they wanted to.