Though it’s not any kind of official rule, there is a popular strain of thought among many Latter-day Saints that girls should only marry a returned missionary. I’ve seen this written as a laudable “goal” in some publications, and have heard it taught to young women in church many times, as well as hearing it as an earnest objective from many young women themselves.
Now, at first, this is a good goal that makes sense. After all, if we want to help the happiness and stability of our children’s marriages–and the homes in which their children will be raised–nothing could make more sense than encouraging girls to seek out the worthiest, most reliably active young men to marry. Certainly, we’ve all seen the heartache and damage caused when women “unequally yoke” themselves to men whose choices might make them regret their own choices, and which hamper the faithfulness of both wife and children.
However, as with the assumption that some have that being sealed in the temple is a guarantee of salvation or exaltation, this goal is ultimately wrong, as it focuses faith on titles, stations, and past actions, rather than on the Savior and the doctrines of the gospel themselves. Yes, a returned missionary is surely more likely to be a faithful, stable mate (at least in terms of church activity) than a man who isn’t, but making that a standard is dangerous in that it trains young women to look for outward, past symbols of faithfulness (or just activity, which is not necessarily the same as faithfulness), instead of a deep, personal, ongoing devotion to discipleship.
In short, telling young women to only consider returned missionaries for marriage is Pharisaic, and denies the reality of the Atonement. Of course, not being an RM myself, I’m surely biased here, but that only means that my point should be taken with a grain of salt, not discarded.