This Measure of Faith also becomes useful in dealing with the enemies (be they Christian or Non) of a believer. For when a person understands that they were a God Hating Idolater for whom Christ died and God justified and promised to glorify then a believer can become an advertisement of mercy for anyone.
When this person is cursed they’re able to bless for that is exactly what our object of faith did for us. We cursed Him, we reviled Him and yet in Him all the families and nations of the world are blessed.
Moreso, if the person actually takes vengeance into their own hand they can be detracting from the Gospel. For God’s Gospel in His righteousness is revealed upon Hiw own revelation of His wrath. True the intermediate wrath of the current sins happening around us but even more in the wrath that was poured out on God’s own son.
A believer who takes the Cause into his own hand and takes revenge, pouring out his own wrath, is effectively standing in God’s place without completing the purpose of God’s revealed wrath. Instead, Paul says “Get out of the way but make room for God’s vengeance”
In this manner a person is actually helping someone else out for back in the day there was this old saying that spoke of a person feeling shame for what they have done. “I have put coals on my own head!” they would think but in Paul’s Gospel he says “Get out of the way for in so doing you’ll help him put his own shame on himselfâ€”you’re helping the man to feel his own shame.”
It’s not a nasty thing but actually conquering evil with good.