The passage from Ephesians describes how a Christian life should be different from a pre-Christian life characterized by futile thinking, darkened understanding, and hardened hearts. It encourages believers to take on a new self based on Christ, let go of deceitful desires, and adopt an attitude driven by guidelines like truthfulness, managing anger, useful work, and avoiding unwholesome talk, all of which point to a way of life that is distinct from what came before faith.