What does the Bible say about hypocritical worship?

In Isaiah 1:10-15, God rebukes the people of Israel for their vain worship and hypocrisy. Despite performing the rituals and sacrifices He instituted, God declares them as empty and abominable because their hearts were far from Him. The people had a form of godliness but denied its power, focusing on the outward expressions of faith without true repentance or sincerity. This theme continues in the New Testament, where Jesus criticizes the Pharisees for their hypocrisy, calling them 'whited sepulchres'—beautiful on the outside but dead within (Matthew 23:27). True worship requires a contrite heart, as emphasized in Psalm 51:16-17, where David states that God desires a broken spirit over mere sacrifices.