The Son of God Appeared for the Purpose of Destroying the Works of the Devil

The Son of God appeared for this purpose to destroy the works of the devil. He has personally conquered in his own person and work the devil, but that doesn't mean his people have the same thing conferred upon them right now. There isn't an instantaneous transformation of everything into its eschatological or eternal state. The effects of the work of Christ get applied slowly but surely and then catechismically at his second coming.