Zac Poonen warns about the danger of hypocrisy, comparing it to the leaven of the Pharisees. He explains that the term 'hypocrite' originates from the Greek word for 'actor', highlighting how some people put on a show of holiness in public but live differently in private. Poonen emphasizes that many hypocrites can be found in churches, where they act pious on Sundays but lead ungodly lives during the week, engaging in negative behaviors like complaining, grumbling, gossiping, and quarreling.

"Beware of the leaven of the Pharisees which is hypocrisy" (Luke 12:1). The word "hypocrite" is actually a Greek word that has been imported into the English language and means "actor". If you went to Greece in the first century and asked people where all the hypocrites were, they would have replied, "At the theatre". The hypocrites come on the stage there and practise their hypocrisy (acting) for a couple of hours and then go home to live their normal lives. In a Hollywood movie, a man may play the part of John the Baptist and act very holy for a short while, because he is an expert actor. But in real life he may be a drunkard and an adulterer. Today most hypocrites are found in churches, where they also act their part for a couple of hours on Sunday mornings. They do a great act of praising the Lord at that time, every Sunday. But if you were to go to their homes during the week however, you will soon discover that they were only acting a part on Sunday mornings. In their normal lives at home, they are not praising God, but complaining, grumbling, gossiping and quarrelling with one another. Are you like that - acting a part for others to see in the church meetings, but quite a different person in your office and in your home?