The Sermon on the Mount is the greatest sermon ever preached. The main question Jesus is answering is: “What is true righteousness?” Jesus flips the “religious script” of the spiritual leaders of the day who believed in a primarily external type of self-righteousness. Jesus, the master teacher, does not begin His sermon by harping on these religious leaders but just points out that character flows from the inside out, not the other way. True righteousness, as Jesus described it, begins internally, in the heart, and flows from there.