So he sat down. After the service ended, the preacher stood at the door shaking the hands of those who were leaving. At school we learn what outward signs of attention will please the teacher. As if donning masks, we style our hair, choose our clothes, and use body language to impress those around us. Over time, we learn to excel at hiding truly serious problems.
People tend to judge by outward appearances and so can easily be fooled.
Matthew Chapters 5-7 announce that the time has come for us to change not just the outside, but the inside. In Jesus' day, religious people tried to impress each other with showy outward behavior. They ostentatiously gave money, wore gaunt and hungry looks during a brief fast, prayed grandly if people were watching, and went so far as to wear Bible verses strapped to their foreheads and left arms. In his famous Sermon on the Mount, Jesus blasts the hypocrisy behind such practices. God is not fooled by appearances.