Why did the Pharisees' zealous rule-keeping produce hypocrisy, pride, and a critical spirit rather than genuine holiness? In this expository message through Mark 7, Leon Pretorius shows that external rules and regulations cannot make us holy because defilement comes from within — from the heart. True transformation is found not in adding do's and don'ts, but in resting in the finished work of Christ, walking by the Holy Spirit, and growing in the knowledge of God's glory.