Jesus rebuked them for being dull.  Dullness, here, is not an intellectual weakness: it is dullness-of-sight ... the inability to see truth after spending so long in spiritual darkness.  They had languished under the burden of relationless religion, and so they had lost their ability to see what pleased the Lord.  In their obsession with ceremonial washing before meals (that was unlikely to remove many bacteria anyway), they missed the point that God was looking for clean hearts.  They could not understand what Jesus meant when He said, "Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them." (Mark 7:15)

Jesus is concerned about what is in people's hearts.  That simmering and sometimes boiling cauldron of evil desires which become evil actions when the opportunities come.  What comes out, in behaviour, simply reveals what is already resident there.  The long list of habitual wrong passions are processed as wrong thoughts and end in behaviour which ridicules the wisdom of God and demonstrates the inner foolishness of the person.  The characteristic of a fool is that he or she lives as though there is no God (Psalm 14:1).

When a heart is not filled with the presence of the living God, many evil desires can be at home there (Matthew 11:24-26).  An outward veneer of religion is merely a comfort blanket to wickedness!  This catalogue of sinful attitudes would have been shocking to devout religionists.  They are designed to be shocking - to alert the hearer and reader, including us, to wake up and realise that these venomous snakes live inside us.  No pious ritual can change the wickedness that lurks within: we need the power of Christ to deal with our hearts.

Hypocrisy (which means ‘play acting’), is the name Jesus gave to such a lifestyle (Mark 7:6-7) - and religious people were in the glare of His searchlight.  As we start to examine ourselves, the liturgical words, "Almighty God, to whom all hearts are open, all desires known and from whom no secrets are hidden ...", should spur us to reject the right of any evil desire to stay inside.  That is much more important than layering another religious role or action on the outside of our busy lives.