Origin and Application:
A double-edged sword is a weapon of potential danger - its edge cuts on both sides. If it is not handled properly, it can hurt you, as much as strike the target as much as it can hurt yourself. In the Book of Hebrews written by Paul the apostle, he describes God’s word as “sharper than any double-edged sword”, because it “penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart.”
Today, a “double-edged sword” is used figuratively to stand for something that has both a good side and a bad side, for example modern technology like the Internet, antibiotics and others.