As a former missionary I would like to give some tips to missionaries serving in the field. Although I served in the "dark ages" of missionary service (before "Preach My Gospel), I feel that giving some words of encouragement might help those on missions or those who are preparing to serve missions.
Missions Are Worth it
Although the savior never said the words "I never said it would be easy, I only said it would be worth it" the principle applies here. Missions are not easy but they are worth it. The skills that I gained as a missionary were paramount, I now speak 2 languages other than English. My confidence is higher, even though the mission was a struggle.
Missions Make Us Better
I have a severe learning disability I was not diagnosed with this until I was in my early 30s. After talking to my therapist, he had indicated that most people with this particular learning disability, barley squeak through high school, and college becomes such a challenge that they quit and end up shutting down. I did graduate high school, but after serving a mission and struggling through I was able to overcome some of the mental blocks that I had with the learning disability and upon returning home I was able to graduate college and able to do those things despite the struggles that I had.
A Mission Allows You to Learn the Scriptures
I know the scriptures 100 fold better than I new on my mission, however, my mission was the only the start. I still have more to know than could ever be known about the scriptures however, I really started learning the scriptures on my mission. Now I can teach my children to learn the scriptures well before their own missions so that they they will know more than I knew.
You Graduate From Being a Child of Christ to a Man or Woman of Christ
I think the biggest thing to remember is that we don't have to stay as children of Christ, the scriptures tell us to be childlike but Lehi exhorted his children to be men ". . . arise from the dust, my sons, and be men, and be determined in one mind and in one heart, united in all things, that ye may not come down into captivity . . ." 2 Nephi 1:21
You can do it the mission may be hard but it is worth it. Work hard and things will work out for your good.
I am glad I served a mission because I was able to overcome some of my own challenges, I could be just like Joseph Smith taught.
"There has been a great difficulty in getting anything into the heads of this generation. It has been like splitting hemlock knots with a corn-dodger [a piece of corn bread] for a wedge, and a pumpkin for a beetle [a wooden mallet]. Even the Saints are slow to understand." (Teaching of Joseph Smith, Chapter 45)
I am so glad that I was able to become better as a result of my mission service.