Religious societies are generally noted for requiring (or at least heavily suggesting) certain activities. For my church, the two-year stint is the most well known. Bringing it up can do one of two things generally. Either it puts a positive spin (because not everyone does do it, can do it, or will do it) or it becomes a point of dissection where they pick apart your experience to see what you learned from it. If it was what it was supposed to be (and this is why religious groups push these types of experiences) you can show how it changed your life, helped you realize the positive aspects of volunteer/community service, or some other beneficial change in your life. For me it enabled me to interact with all people within the social strata which is beneficial in a job where interaction with everyone from the derelict with a narcotic fix to the SUV driving/medicaid carrying self-entitled public to the person who has waited two hours for their prescription and is reasonably frustrated after having been told it would take 1/2 hour so she waited with her sick newborn in the store the whole time.
Someone familiar with this aspect can use it in an open file interview to find out exactly how much you put into it or if you were just using it as fluff to pad your app. If it's fluff that's obviously bad. Kind of like padding your service hours and getting caught. So yeah, if you did it because of expectations, didn't get anything out of it, and wouldn't use it for any other reason than padding, I'd suggest not to. Kind of like the Eagle Scout who was pressured by his parents to get it and only did so so that he could get .....driver's license, car, some other bonus from the parents. If they ask what you learned from your years at Boy Scouts, what would you be able to tell them, if you struggle with the answer how bad does it look?
One of my interviewers was Mormon and I wasn't asked about my mission, even though I mentioned it during the interview. Had I been asked about it I would have been entirely prepared to discuss it, I can't say that for everyone I met on my mission.