Romans 12:20, “Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.”
What does this strange little phrase mean: “heap coals of fire on his head?” There is actually a fair bit of debate about what this little phrase might mean, but one suggestion is this: In ancient times when a city was besieged, the people of that city would throw down burning liquid or coals onto their enemy to prevent them from scaling the walls. If your hair is on fire, it’s hard to use your sword, and if your face is burning, it’s pretty tough to aim your bow and arrow.
The principle as it relates to loving our enemies is this: When you oppose your enemy with love, they find it difficult to keep on attacking. Proverbs 15:1 says, “A soft answer turneth away wrath: but grievous words stir up anger.” Does that mean we sit by and say nothing? No! But our answer must be gentle and humble.