Lesson 5 teaches that understanding salvation begins with understanding sin. Sin entered the world through Adam’s disobedience, bringing guilt, death, separation from God, and a sinful nature inherited by all humanity. Genesis 3 records the historical Fall, while Romans 5 contrasts Adam’s condemnation with Christ’s offer of justification, grace, and eternal life. The Law exposes sin and points people to Christ, the only Savior, since self-effort cannot save. Satan’s pride and deception initiated humanity’s fall, yet individuals remain responsible for their own sins. The lesson emphasizes that Christ alone provides forgiveness, righteousness, and new life.