“Write this letter to the angel of the church in Pergamum. This is the message from the one with the sharp two-edged sword:” Revelation 2:12
A ‘double-edged sword’ is a weapon that brings about death. Sometimes death is exactly what we need. There may be things in our lives that are not pleasing to God. These need to be brought under His authority and removed from our lives. If we are going to find ourselves coming against the enemy, we need to be prepared. We need to have One on our side who has, available to Him, an instrument for warfare.
It seems to make plain that the sword here refers to the Word of God. Its representation as a double-edged sword indicates on the one hand the sword as the Word of God which separates the ones who are the vessels of grace from condemnation with the world, and which by its promises and message of salvation cuts loose the chains of sin and condemnation which bind the helpless sinner. On the other hand, the same Word of God is the means of condemnation and rejection for those who refuse the message of grace. The Word of God is at once the instrument of salvation and the instrument of death. This twofold character is especially pertinent to the church at Pergamos, which needed to be reminded of the distinct position of those who are true Christians as opposed to those who reject the gospel. “For the word of God is alive and powerful. It is sharper than the sharpest two-edged sword, cutting between soul and spirit, between joint and marrow. It exposes our innermost thoughts and desires. Nothing in all creation is hidden from God. Everything is naked and exposed before his eyes, and he is the one to whom we are accountable.” (Hebrews 4:12-13)
“The Word gave life to everything that was created, and his life brought light to everyone. The light shines in the darkness, and the darkness can never extinguish it.” (John 1:4-5) Jesus is the Word.