What does the Bible say about self-deception in faith?

The Bible articulates a clear distinction between true fellowship with God and self-deception in faith. In 1 John 1:6, it states, 'If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth.' This emphasizes that a genuine relationship with Christ cannot coexist with a lifestyle characterized by sin and darkness. The implication is profound: loving and following Christ necessitates a life reflecting His light and holiness. Any claim of fellowship that does not align with a transformed life is ultimately an act of self-deception.