Part of not thinking of ourselves more highly than we ought (Rom 12:3) is recognizing our incompetence to judge other human beings. We have all experienced the frustration of attempting something with the best intentions in the world and being criticized when our actions are misinterpreted by another human being. We probably also have all experienced the embarrassment of someone assuming the best of us when our intentions were truly just as mean or worse than what they appeared to be. Even when we "know" that someone has mistreated us and deserves to be repaid in kind, the Lord calls us to pretend their intentions were better than they seem and allow Him to bring about justice. Even when we have reasons to protect ourselves from further harm, or to pursue justice through the legal system, we don't have reason to repay them with the malicious spirit we see them acting out toward us. And most of the time, honestly, we need to simply let God be the one who determines whether they need to be punished or whether their intentions were good although the actions were not.