John Piper in Think: The Life of the Mind and the Love of God:
‘This people honors me with their lips, but their heart is far from me; in vain do they worship me’” (Mark 7:6–7). In other words, Jesus says that external actions—even religious ones directed toward him—are not the essence of worship. They are not the essence of love. What happens in the heart is essential. The external behaviors will be pleasing to God when they flow from a heart that freely treasures God above all things.