Satan, though decisively defeated at the Cross by Christ, remains dangerous, as he desperately seeks to destroy believers and God’s work. Drawing from Isaiah 14 and Ezekiel 28, this study describes Satan’s origin as the beautiful, exalted angel Lucifer who fell through prideful rebellion to try to be “like the Most High”—becoming the adversary who schemes against God’s people. Believers must not be ignorant of his devices but stay strong in the Lord, maintaining a consistent walk and standing firm in the armor of God.