We humans are not very good at living up close with others. This is especially true when we have a history of conflict with those others. Reconciliation isn’t easy. No matter how much you might want healing, it’s hardly ever a matter of just everybody getting on and pretending the hurts didn’t happen.
In Paul’s letter to the Ephesians, he says some very important, fundamental things about peace and reconciliation, and gives many other very practical teachings about how to live together in light of these truths.