"You are called to represent the Savior. Your voice to testify becomes the
same as His voice, your hands to lift the same as His hands. . . . So, your
calling is to bless lives. That will be true even in the most ordinary tasks
you are assigned and in moments when you might be doing something not
apparently connected to your call. Just the way you smile or the way you
offer to help someone can build their faith. And should you forget who you
are, just the way you speak and the way you behave can destroy faith."
(Henry B. Eyring, "Rise to Your Call," Ensign, Nov. 2002, 76)
For me, the first thing that comes to mind is a member of the priesthood, like a bishop, who has the ability to act as a representative of God in many different situations. However, I really loved the reminder that Mormon posted about how everyone is a representative of Christ. Thanks for that, I need to remember that.
My first thought is the Prophet. I think of him as being the Lord's representative. However, any church member, living righeously in the right setting is the Lord's representative. I remember on my mission, we were taught to introduce ourselves as the Lord's representatives. As a Home Teacher, you represent the Lord in the home of your familys. I suppose even a Primary teacher is the Lord's representative to his or her class.
When I heard the Lord's Reprensentative, without any doubt, the Prophet comes to my mind. He is the one here on Earth to receive revelation from God and act as his official representative but I do agree that when we live righteous lives we can become reprensentatives of him too.