In an article I read, a man noted some things he learned while on deputation.
1. Increased confidence in God and self.
2. Flexibility. You must be ready at all times for all things. You must be ready to teach the children or silver saints. As one man put it, "Be ready to preach, pray,or die at a moments notice."
3. Patience. I think you get this one!
4. Learn to meet new people. If you can not do it here, you won't do it there.
5. Learn to be an alien. You go into churches where you do not know anyone and are the "outcast". Welcome to the mission field.
All of these things will be exactly what you will face on the missionary field. You will have a growing dependence upon God for you can not do it. You will have to be all things as the church is being started. You will learn how to stand in line just to pay a bill. You will meet new people and many times feel like an alien. (You are!)
The lessons you are learning today on deputation are making you into the person God will use on the field.