I remember from my time as a youth director learning the phrase, “heart transformation, not behavior modification.” It was a helpful way to think about working with young people, especially young people that were not coming from church backgrounds. If we wanted to see positive change in their lives it was not going to come from enforcing a bunch of rules (though boundaries and rules are necessary), but from helping them have a relationship with Jesus that transformed them from the inside out.
I think this is what Jesus is getting at in the first part of Matthew 15. In talking about the Pharisees, Jesus quotes the prophet Isaiah, “They honor me with their lips, but their hearts are far from me. They worship me in vain; their teachings are merely human rules.”
I don’t want to discount the impact that our habits and disciplines can have on us. However, if our habits and disciplines and rules are only about making us look good and not about the ongoing transformation of our hearts, then we tend to become self-righteous and judgmental, just like the Pharisees. It is not that the Pharisees were wrong about the laws, they were experts. The problem of the Pharisees was that their life’s worth and meaning were based on following the laws and passing judgment against those who did not follow them as well.
Jesus is teaching a different way of life and of being in the world. Our worth and meaning are not from being the best rule followers, but from having a heart that is in tune with God’s. Our worth and meaning (and salvation) are not earned by being good people or following all of the rules, but by receiving God’s grace through faith. As I allow God’s grace to fill my life, it transforms the way I see the world around me and how I interact with others. Rather than simply changing my behavior, I am experiencing a transformed life.