What does it mean to heap burning coals on your enemies heads?

“If your enemies are hungry, feed them. If they are thirsty, give them something to drink. In doing this, you will heap burning coals of shame on their heads.” – Romans 12:20

I always used to wonder about this statement, it seemed to me to be a saying that had lost its meaning over the years or perhaps through our cultural differences. The old fundamentalist me used to think that it meant that we should be nice to people who didn’t deserve it because one day God would judge them and that their jerkiness in spite of our niceness would be something else that would count against them one day.Thankfully, I let go of the ‘be nice with an agenda’ mindset a long time ago but it was only recently that I arrived at a satisfactory interpretation of what this verse actually meant.
It all came together while I was reading through Isaiah chapter 6 where verses 5 to 7 say the following:-

Then I said, “It’s all over! I am doomed, for I am a sinful man. I have filthy lips, and I live among a people with filthy lips. Yet I have seen the King, the LORD of Heaven’s Armies.”
Then one of the seraphim flew to me with a burning coal he had taken from the altar with a pair of tongs. He touched my lips with it and said, “See, this coal has touched your lips. Now your guilt is removed, and your sins are forgiven.”

I was struck at the imagery here where the burning coal removed Isaiah’s guilt. The passage immediately made me think of Romans 12:20 and I started to wonder if there were any other references to burning coals in scripture. It turns out that there are quite a few (13 I think) but I would like to focus on the 2 that are most relevant to Romans 12:20 (which is a direct quote from Proverbs 25:22). The first is found in Leviticus 16 and deals with the sin offering that was performed on the day of atonement, verses 11 to 13 read:-

 “Aaron will present his own bull as a sin offering to purify himself and his family, making them right with the LORD. After he has slaughtered the bull as a sin offering, he will fill an incense burner with burning coals from the altar that stands before the LORD. Then he will take two handfuls of fragrant powdered incense and will carry the burner and the incense behind the inner curtain.  There in the LORD’s presence he will put the incense on the burning coals so that a cloud of incense will rise over the Ark’s cover — the place of atonement—that rests on the Ark of the Covenant. If he follows these instructions, he will not die.

The second is found in Numbers 16:46:-

And Moses said to Aaron, “Quick, take an incense burner and place burning coals on it from the altar. Lay incense on it, and carry it out among the people to purify them and make them right with the LORD. The LORD’s anger is blazing against them—the plague has already begun.”

So the burning coals have to do with the removing of sin and guilt which is important as we return to our passage in Romans because we are now able to harmonize it with the way that Jesus dealt with His enemies and the manner in which His disciples are supposed to follow Him. In turning the other cheek, in going the extra mile, even when something has been unfairly asked of us and in blessing our enemies we learn to fight like our King who laid down His own life at the hands of His enemies, knowing that His death would be the very thing that would make life (in Him) accessible to them.

What Paul is sharing in Romans 12 is that rather than getting one over your enemies, we can win them over by doing good. The verse that follows the burning coals one says, “Don’t let evil conquer you, but conquer evil by doing good.” This is not an easy teaching to follow, it is foolishness to the natural mind because to the world you will look like you are losing, when you are wronged and retaliate with kindness, when you are persecuted and respond with forgiveness and when you are taken advantage of but counter with service you are heaping burning coals on your enemies heads, not that they might be destroyed but that they might find life through the testimony of self sacrificial love shared with them.