I used to read this Bible verse and say, "Word of God sword of the spirit got it. Just like Ephesians 6." But is that what this author is really saying?
Ephesians 6:17 says that the sword of the spirit is the word of God. But Hebrews 4:12 says that the word of God is sharper than a sword.
In other words, Hebrews 4:12 says that the word of God is UNLIKE a sword. In what way? Well, a sword is dull; the word of God is sharp.
What is sharper than a double-edged sword?
The word of God (in this description) isn't a crude slashing instrument. It performs delicate exploratory surgery; it lays bare the human heart, revealing its thoughts and intents.