We should read the Sermon on the Mount this way. Jesus is not demanding we live his way in order to get his blessing or get into heaven when we die; he is simply telling the truth about reality. He warns against lust, not because he is a prude but because he knows it destroys human lives when unchecked. He tells us not to worry, not because it will give us ulcers but because people who live with him in the kingdom of God need not worry; it is a waste of time. Lust and worry, judgment and anger, retaliation and pride are never good or beautiful, and never lead to freedom. In fact, they are a flight from freedom. We cannot find happiness or joy apart from a life of obedience to the teachings of Jesus….God is not being stingy and withholding joy apart from our obedience; there simply is no joy apart from a life with and for God….The question is not, “What will I have to give up to follow Jesus? but rather, What will I never get to experience if I choose not to follow Jesus? The answer is clear: we will forfeit the chance to live a good and beautiful life.
James Bryan Smith, The Good and Beautiful Life: Putting on the Character of Christ (Downers Grove: IVP, 2009), 30-31