When my mother or I ask that to my father, he usually gets all worked up and starts enumerating the reasons, lifting one finger at a time as to show us how it must be true the more fingers are up. His speach normally goes like: "Well, it is the right religion, because we are the only ones who (lifts hands up): don't go to war, beleive Jesus is not God, preach, have congreations like the first christians, don't celebrate pagan holidays, don't take blood, are not voting"...etc. Sometimes he can find more. It's sad that he don't see that he's just running in a circle, because most of what he says is like saying, well, we are right because we follow what the WT says, and they are right for sure.
So I say....but Mormons preach, Jews don't celebrate the holidays (I think), most have congregations, it does't work because then he shows me all his finger, waving them around and says "but none of them have it ALL!"