The sermon examines the biblical distinction between genuine miracles from God and deceptive signs empowered by Satan, using Simon the Sorcerer in Acts 8 as a primary case study. It argues that while miracles served to authenticate apostolic messages in the early church, believers must now test all spiritual claims against the authority of Scripture rather than relying on supernatural phenomena. The preacher critiques modern charismatic movements and Roman Catholic Marian apparitions, asserting that teachings contradicting biblical truth indicate demonic origin regardless of any accompanying signs. Emphasizing the danger of false prophets and the necessity of doctrinal purity, the message urges the audience to reject gullibility and anchor their faith exclusively in the verified Word of God. Ultimately, the sermon calls for sober discernment, reminding listeners that salvation and spiritual life are secured through Christ alone, not through works or miraculous experiences.