Why are all Mormon male missionaries called Elders?
Mormons believe that since we are all children of God, we’re all brothers and sisters in faith. This is why, when we attend meetings, we tend to call each other “Brother so-and-so” or “Sister so-and-so” (which makes life so much easier for me, because I’m terrible with names). When women enter the mission field, the goal is to put our personal issues aside and throw ourselves into serving God. This is why female missionaries go by “Sister” rather than their first names. It’s a reminder, really, of their purpose. As for the men…well, for us, “Elder” is an office of authority in the church. Before male missionaries enter the field, they’re ordained with this authority. Like the women, they’re also trying to throw themselves into the work and so go by the title of their office–along with their last names–rather than their first names. When they return from their missions, they typically return to “Brother” rather than “Elder.” Hope that didn’t confuse you.