Paul’s last item in the armour of God is the sword of the Spirit, the word of God (see also Heb 4:12). A double-edged sword made it easier to penetrate, as well as to cut in every way; Eugene Peterson likens this to the sharpness of a surgeon’s scalpel. God’s Word has the power to reach the heart, the very centre of actin, and lays open the motives and feelings of those it touches.
God’s words are powerful (see Heb 1:3). They have the power to sustain us, to bring things into being, to create and to give life. We need God’s Word to guide us and lead us in life, to expose lies and to keep us in the paths of truth. We need to soak ourselves in the word of God and be able to wield this sword wisely and well.