The apostle Paul completes the whole armor of God by adding "the Sword of the Spirit, which is the Word of God."  In the 21st century, Paul might choose the Taser as a symbol of the Word of God.  A Taser neutralizes the enemy with a surge of power.  The Taser of the Spirit neutralizes the enemy with a surge of divine power through the Word of God.  The word in Ephesians 6:17 refers to specific sayings from the Word of God.  We need to fill our minds with the sayings of God as a powerful defense against the enemy.