Matthew 23:13-15

However, their entire outlook on religion had one fundamental effect. It made it a thing of thousands upon thousands of rules and regulations, rendering it an intolerable burden. To make things worse, the Pharisees would not allow the slightest relaxation of the rules, even for mercy's sake. Their confessed purpose was to build a fence around the law, and they would not relax or remove one regulation. By all this, they prevented people from an opportunity to enter the Kingdom of God. The Pharisees shut the door to the Kingdom of God with their hypocrisy, which made them evil emissaries.

The Pharisees converts were attracted to Pharisaism, not to God. And by getting caught up in the details of their additional laws and regulations, they missed the point of God to whom the laws were intended. A religion of works pressures people to surpass others in what they know to do. Thus, a hypocritical teacher was likely to have students who were even more hypocritical than himself.