Matthew 6:5
When thou prayest, thou shalt not be as the hypocrites are.
What is a hypocrite? Someone who pretends to be something that they are not. Jesus condemned hypocrisy very strongly simply because the hypocrite put on a show for others to think that he was righteous when, in fact, his heart was not right with God. Are you the same every day of the week, or do you “behave” on Sundays? This is a very searching question and one that needs to be answered even by those of us who are not young any more.