"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.” (Romans 12:20)
What in the world does that mean?
"For love is strong as death, its jealousy hard as the unseen, its burning coals as burning coals of fire, the blaze of Yah. Many waters cannot quench love, nor can streams overwhelm it." (Song of Solomon 8:6-7 CV)
I think to "heap coals of fire on his head" means to show the love of God to your enemies. That is the way God deals with His enemies, and believers should try to do so - although it is extremely hard and seems foolish to us! I try and usually fail.
"God demonstrates His own love toward us, in that while we were still sinners, Christ died for us." (Romans 5:8)