The Great Wall of Gorgan is one of the most impressive structures ever built. Constructed 1,500 years ago to protect the Persian Empire from Enemy raiding parties, it stretches for more than 120 miles in northwestern Iran. Recent excavations have revealed the quality and careful engineering that went into it. At any given time, about 20,000 soldiers would have been stationed along the wall to protect the border.

A strong defense is an important dimension of Spiritual warfare. “Finally,” Paul wrote, “be strong in the Lord and in his mighty power” (v. 10). Having discussed God’s purposes and plans in salvation, and having urged the Ephesians to live worthy of the gospel and to be filled with the Holy Spirit, he now moved to close his epistle with an exhortation regarding spiritual warfare.

Christ has finished His work of redemption and is seated at God’s right hand, far above all other spiritual powers. Yet at the same time, the battle rages on in the history of the church and in our own lives. We shouldn’t try to fight in our own strength but instead rely on God’s “mighty power” given to us in His “full armor” (v. 11).

Spiritual warfare consists of standing against the devil’s schemes. Satan is the enemy or adversary of God and the gospel, so by definition any plan or intention he has is wicked. He and his fallen angels, all the “spiritual forces of evil in the heavenly realms,” take every opportunity to try and undercut God’s work in the world (v. 12).

We shouldn’t view other people as the enemy. They are made in God’s image and loved by Him. Instead, our real enemy and the real battle are spiritual (see 3:10–11).

The literary genre of fantasy is one way Christian writers have explored what spiritual warfare might look or feel like. Three insightful novels that take spiritual realities seriously are That Hideous Strength by C. S. Lewis, War in Heaven by Charles Williams, and The Alpine Tales (actually four books) by Paul J. Willis.