While C.S. Lewis’s interpretation of a demon writing letters of encouragement and rebuke to his nephew can be quite terrifying, the biblical reality is that the reality of Satan is even more terrifying. Satan was not only involved in the first cosmic betrayal of God and his newly created couple, but was continually involved in the affairs of humanity in a restricted, but relatively free fashion in the Old Covenant. In those days, Satan acted in contempt for God and his commandments. The Hebrew nation—graced with the protection of God—chose rather to follow the footsteps of the Father of Lies than to trust in their creator, Yahweh. The pages of the Old Covenant are replete with narratives where demonology, occult practices, idol worship, desecration of holy places, law-breaking, and a complete disregard for purity abound.
It is in the midst of this idolatrous context where Messiah descends. Though Israel was given a robust tradition rooted in the prophetic writings (which were filled with warnings about idolatry), she chose not to fulfill her calling as ambassadors to the nations. God—in his wisdom and providence—provided a way of redemption for his chosen nation. Instead of abolishing her, he re-made her. This re-making process meant that Israel was no longer an isolated nation, but a holy nation composed also of the Gentiles. With the walls of partitions broken down (Gal. 3:28), Paul refers to this Israel as the Israel of God (Gal. 6:16). This new nation of holy priests now (I Peter 2:9) submits to One Lord through one faith and one baptism.
The Church–Jew and Gentile in Christ—does not battle the evil forces of this world as a solitary nation, but as a Holy Nation bound to One true Victor who will no longer fall for the whispers of the serpent in the Garden. This true and final Adam crushed the serpent (Heb. 2:14; Rom. 16:20), ascended into heaven, and rules and reigns from the right hand of the Father.
However, this reality is not an exhortation to idleness and passivity. Rather, it is a call to arms, because the Devil is still looking to devour the sons of men (I Peter 5:8), seeking to add weak men to enter into the fold of apostates (Heb. 6).
Augustine was fond of saying that the devil is bound like a dog, but a bound dog still bites if we dare by our sin approach him.
The words of the affectionate uncle, Screwtape should serve as a sober reminder that evil exists, and that the seduction of the serpent continues to be as poisonous as it was in the Garden. May our faith endure, and may it increase with each rejection of the wiles of the evil one.