Why is the concept of Satan's defeat important for Christians?

Satan's defeat is a central tenet of Christian faith because it underscores Christ's victory over evil. Revelation 12 reveals that despite Satan's attempts to destroy the Messiah and thwart God’s plan, he was cast out and could not prevail against God's purpose. This victory is essential for Christians as it assures them that they are more than conquerors through Him who loved us. Believers can find comfort and strength in knowing that, while the adversary may rage, his doom is assured, and they are secure in the kingdom of Christ. This truth empowers Christians to live boldly, trusting in God's promises as they navigate a world filled with spiritual opposition.