The final piece of armour is the sword of the Spirit. It’s described as the word of God, so some of us have thought of it as the Bible. That’s not how the Ephesians would have understood it when they received this letter: they didn’t have Bibles.
The word of God is everything our heavenly sovereign decrees for his earthly realm. What God declares is a sword because cuts it through any opposing force.
When God said, “Let there be light,” there was light because God decreed it. When darkness engulfed God’s world, the Word became flesh and dwelled among us in the brightness of his glory. The dark powers could not overwhelm him, for the Word was God. Jesus is God’s decree for the world (John 1:1-14).
Rebels killed God’s anointed ruler, but the Spirit of holiness did not allow this evil to stand. The Spirit spoke a word that cut through the enslaving powers, piercing death itself, raising up God’s anointed ruler, appointing this Son of David as ruler over us all (Romans 1:4).
The word of God — God’s declaration that Jesus is Lord and the earth is rescued in him — cuts through every other power claim. God’s anointed speaks with the Sprit’s authority, so a mere whisper on his lips overcomes rebellion against his reign (Isaiah 11:4).
The Spirit’s declaration — the powerful life-giving word that raised Jesus from the dead — is now at work in us too: raising us up with Christ, animating us as sons of God, the community alive in the Son (Romans 8:11).
Human rulers use swords to make war, to kill people who won’t yield to their power. The Spirit uses his sword not to cut people down but to cut them free from oppressive powers, not so they die but so they live in the reign of Christ.
With modern technology, we’ve created many weapons of war, but no weapons of peace. The sword of the Spirit is the only weapon that frees without killing, that brings us together as one world under the ruler decreed by God.
So, how do we wield the Spirit’s sword? Not merely by quoting Bible verses at people, but as ambassadors announcing Christ’s kingdom. We’re heralds of the good news that God has raised him from the dead and installed him as our king, calling everyone to place their allegiance in God’s anointed and live under his kingship.
The sword of the Spirit is in our mouths as we proclaim and embody the living declaration of Christ’s kingship. This is the sword that sets people free, the Spirit’s word that regenerates people out of death, into life in the reign of Christ.
That’s the life-giving peace-making power of the Spirit’s sword in our mouths.
What others are saying
Rudolf Schnackenburg, The Epistle to the Ephesians: A Commentary (Edinburgh: T&T Clark, 1991), 280:
Possibly the author of Eph. has in mind the passage in Is. 11:4 where ‘word’ and ‘breath’ (πνεῦμα) stand parallel in the description of the coming Messiah. Already in v. 14a (girding with truth) he has drawn from the following passage in Is. 11:5. Thus here again a statement about the Messiah is transferred to God’s soldier. The ‘word (ῥῆμα) of God’ with which he fights the battle as if with a sword is not defined more closely (without an article) and in the context surely means nothing other than the Christian message, the Gospel (cf. Rom. 10:8; 1 Pet 1:25). The ‘Gospel of your salvation’ (1:13) held firmly in faith and held up to one’s enemies in truth, proves itself in battle through the power of the divine Spirit which is inherent in it.