What does Mark 7:23 mean?

Jesus is bringing in a more complete way of thinking. The law proves insufficient for salvation because although it somewhat controls people's actions, it doesn't change their hearts. In fact, Jewish leadership finds it easier to add unnecessary traditions than to honor the laws God gave them. Following the law doesn't make you holy; your heart determines if you are truly clean in your nature or not.

Jesus' latest argument with the scribes and Pharisees is over whether eating something unclean can make a person unclean. The religious leaders fear that accidentally eating food that has touched something unclean will make them spiritually removed from God. Jesus explains that a heart hardened from within is the only thing that can make someone spiritually unclean, and He spends the next three sections living out this truth.

First, He will seek refuge in a Gentile town and heal the daughter of a woman whose people have a long history of persecuting and abusing Jews (Mark 7:24–30). Next, He will return to the Gentile region where He'd healed the man with a legion of demons and heal a great many people (Matthew 15:29–31), including a deaf man (Mark 7:31–37). Finally, He will decisively show the foolishness of worrying about unclean food by providing a meal for four thousand people in a Gentile nation.