Once there was a man who dreamed that he was in a great hall where all the religions of the world were gathered. He realized that each religion had much that seemed desirable and worthy.
He met a nice couple who represented The Church of Jesus Christ of Latter-day Saints and asked, “What do you require of your members?”
“We do not require anything,” they replied. “But the Lord asks that we consecrate all.”
The couple went on to explain about Church callings, home and visiting teaching, full-time missions, weekly family home evenings, temple work, welfare and humanitarian service, and assignments to teach.
“Do you pay your people for all the work they do?” the man asked.
“Oh, no,” the couple explained. “They offer their time freely.”
“Also,” the couple continued, “every six months our Church members spend a weekend attending or watching 10 hours of general conference.”
“Ten hours of people giving talks?” the man wondered.
“What about your weekly church services? How long are they?”
“Three hours, every Sunday!”
“Oh, my,” the man said. “Do members of your church actually do what you have said?”
“That and more. We haven’t even mentioned family history, youth camps, devotionals, scripture study, leadership training, youth activities, early-morning seminary, maintaining Church buildings, and of course there is the Lord’s law of health, the monthly fast to help the poor, and tithing.”
The man said, “Now I’m confused. Why would anyone want to join such a church?”
The couple smiled and said, “We thought you would never ask.”
The rest of the talk is here: https://www.lds.org/general-conference/2013/10/come-join-with-us?lang=eng
The same question is: Why would I want to go on a mission? I'm giving up so much. There's a lot that I've been promised by Heavenly Father for going on a mission that I just don't want to give up. That's why, for the last 4 years, I've been preparing for this moment that stands before me now. There's so much that each missionary comes back with, that the sacrifice they made to be there suddenly seems so small compared to the blessings.
Why would I do this? Why do I know that I'm doing the right thing? There's one answer: it's because I know that it's true. I know that it's true, because the Spirit of God has answered my prayers and has told me that it's true. I want all others to come closer to God and be happy. Life will never be without challenges or trials, but with the Gospel, I know what's coming and who I can turn to to get through it all.