In theatre, as well as the movies, the quality of a performance is based on the credibility of character. If you are a good actor the audience will not see you, but rather the character you are portraying. To be believable, you have to spend time studying your character and work at developing your character's attributes.
In this teaching, David states that the two primary types of actors in theatre are either technical or methodical, and explains how in the Church today we have both as well. More importantly though, he expounds on the need to study the character (Jesus) we are portraying, so that when people see us, they will actually see Him. The big question is: "How believable are you?"