Definition and Context: In biblical terms, defilement refers to the state of being unclean or impure, particularly in a spiritual or moral sense. True defilement, as taught in the Scriptures, transcends physical impurity and focuses on the condition of the heart and the moral actions of an individual.

Old Testament Understanding: In the Old Testament, defilement is often associated with ceremonial uncleanness, which could result from contact with certain animals, diseases, or dead bodies (Leviticus 11-15). These laws served to set Israel apart as a holy nation and to teach the people about the holiness required by God. However, the prophets began to emphasize that true defilement was not merely external but internal, rooted in sin and rebellion against God. Isaiah 1:16-17 calls the people to "Wash and cleanse yourselves. Remove your evil deeds from My sight. Stop doing evil. Learn to do right; seek justice and correct the oppressor."

New Testament Revelation: Jesus Christ further clarifies the concept of true defilement in the New Testament. In Mark 7:14-23 , Jesus teaches that it is not what enters a person from the outside that defiles them, but what comes from within. He states, "For from within the hearts of men come evil thoughts, sexual immorality, theft, murder, adultery, greed, wickedness, deceit, debauchery, envy, slander, arrogance, and foolishness. All these evils come from within, and these are what defile a man" (Mark 7:21-23). This teaching shifts the focus from external observance to the internal state of the heart.

Apostolic Teachings: The apostles continue this teaching, emphasizing that true defilement is a matter of the heart and spirit. In 1 Corinthians 6:9-11 , Paul warns against various sins that defile a person, but he also offers hope through the cleansing power of Jesus Christ: "And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God."

Practical Implications: True defilement, therefore, is not about ritual purity but about moral and spiritual integrity. Believers are called to live lives that reflect the holiness of God, avoiding actions and attitudes that corrupt the heart. James 1:27 encapsulates this by stating, "Pure and undefiled religion before our God and Father is this: to care for orphans and widows in their distress, and to keep oneself from being polluted by the world."

Conclusion: The biblical teaching on true defilement challenges believers to examine their hearts and actions, seeking purity and holiness through the transformative power of the Holy Spirit.