Young men, prepare to serve as missionaries. Going on a mission teaches you to live the law of consecration. It may be the only time in your life when you can give to the Lord all your time, talents, and resources. In return, the Lord will bless you with His Spirit to be with you. He will be close to you and strengthen you.
Elder Robert D. Hales (Gen Conf Apr 1996)

"It is the deepest desire of my heart to have every member of the Church worthy to enter the temple."2 If our young men or young women, on their way to the mission field, go to the temple unworthily, it is a great mistake. We must prepare them for the temple first, and then they will be prepared for missions. President Hunter said, "Let us prepare every missionary to go to the temple worthily and to make that experience an even greater highlight than receiving the mission call."
Pres Howard W. Hunter

Young men, wherever you are called will be right for you, and you will learn to love your mission.
President Thomas S. Monson (Gen Conf Apr 1995)

The prophet has asked you young men to serve, the world desperately needs you to serve, and you need to feel the power and growth from serving and teaching others
Elder Hugh W. Pinnock (Gen Conf Oct 1993 )