Have you ever heard the story of the frog in the kettle? Place a frog in boiling water, and it will immediately jump out. But place it in room-temperature water and gradually increase the heat, and the frog will stay put until it's too late. While this analogy may be more folklore than science, it illustrates a profound truth about human nature.

In Jesus' day, the religious system had gradually shifted from God's original intent. Like that proverbial frog, the people didn't notice the slow drift from true worship to ritualistic religion. The Pharisees had added layer upon layer of rules and traditions until the heart of God's law was nearly unrecognizable. As Jesus said, "Making the word of God of none effect through your tradition, which ye have delivered" (Mark 7:13).

I wonder how many of those sincere worshippers realized something was amiss?