Sin is defined as the transgression of God's law, specifically the Ten Commandments. It represents surrender to Satan, separation from God, and rebellion against Him. Sin manifests through actions prompted by the flesh and influences from the kingdom of darkness. Key issues include distraction, desensitization, division, and deception, which the devil uses to lead believers away from spiritual truth. Embracing righteousness and following God simplifies life, contrasting the complexity introduced by sin.