Jesus answers these teachings by saying he hasn’t come to abolish the law, but to fulfill it. He rebukes the Pharisees by saying our righteousness must exceed the Pharisees or we will not enter the kingdom of heaven. His first example of their hypocrisy is about murder. The Pharisees taught that just avoiding the act of murder was considered as keeping the law, making one righteous before God. Jesus however, makes implicit references to Leviticus 19:17, where they are commanded not to hate your brother Israelite in your heart, and uses it to demonstrate that such hate is a violation of the law before God, just as heinous as actual murder.
The Pharisees taught that if one abstained from adultery, they were righteous before the law. But Christ show implicitly refers to the 9th Commandment to show that coveting or lusting after a woman who is not your wife is just as heinous a sin before God, demanding of hell. Hence, once again, we are not righteous before God.
The Pharisees taught that because the Mosaic law allowed for divorce that divorce could be granted for any reason so long as a certificate of divorce was given, thus maintaining the legal righteousness of the person. Jesus says, no again.
Jesus then looks at the nature of the ritual practices that supposedly demonstrate outwardly one’s righteousness such as giving alms, prayer, and fasting. He says that performing these deeds for the purpose of demonstrating one’s righteousness before God is hypocritical and is a twisting of these practices.
Jesus then speaks of judging whether another person stands righteous before God. He demonstrates that in doing so, we condemn ourselves, because we are similarly unrighteous.
He then says to seek entry into the kingdom of God through the narrow gate. It was probably common teaching in the Church at the time that Jesus is the gate by which we gain entry into God’s presence (reference John 10:7). This is the point at which Jesus addresses the false teachers and prophets. Jesus speaks of knowing them by their fruit. Judging by the fact, that Jesus mentions both the actions of the Pharisees, and references their false teaching, the bad fruit most likely deals with both, knowing them by their evil deeds and by their teaching which are aberrations from God’s Word. This is reinforced by the next parable where Jesus states that anyone who hears his words AND puts them into practice is like a wise man who builds on rock.