Revelation 2:12, 16
This sword is the two edge sword of truth that is
used to defeat false prophets and the Anti-Christ.

Revelation 2:12, 16

2:12   And to the angel of the church in Pergamos write; These things saith he which hath the sharp sword with two edges;
2:16   Repent; or else I will come unto thee quickly, and will fight against them with the sword of my mouth.