Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place, and with your feet fitted with the readiness that comes from the gospel of peace. In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one. Take the helmet of salvation and the sword of the Spirit, which is the word of God.Ephesians 6:14-17 NIV
The final piece of armor Paul discusses, is not really armor. Armor serves to protect the wearer. This piece though is used to attack the opponent. The Roman sword was short and flat. And it was a deadly weapon for close-in fighting.
The sword we are instructed to take up is the sword of the Spirit, the word of God. The sword of the Spirit. This sword that we have is the property of the Holy Spirit. He equips us with it and teaches us how to use it. There are other swords available today, the Koran, the Hindu holy writings, philosophy or science books. Some of them have limited value. But none will help you in taking the fight to the enemy.
What is this sword of the Spirit? Paul identifies it as the word of God. While this term is often applied today to the Bible. I believe it is more than that. The Bible contains the words of God. But it itself is not the word. Jesus is the Word (John 1:1-3) and he has the words of life (John 6:68). The word of God is what he speaks to us.
But for us today, the Bible, energized by the Holy Spirit, is our sword. Apart from the Holy Spirit it is nothing more than words on a page. But when the Holy Spirit takes it and applies it to our lives it is powerful and effective (Heb. 4:12).
Get to know the word and allow the Spirit to teach you from it. Train in its use. And take it into the battle with you, advancing against the enemy who is powerless against it.