If it is possible, as much as it is up to you, be at peace with all men.
Two qualifiers sit inside this one short sentence, and both of them are gifts. If it is possible admits that sometimes peace is not. As much as is up to you draws a line at the edge of your own responsibility.
Many of us live as though neither qualifier existed. We take the full blame when a relationship collapses, as if another person’s choices were ours to make. Or we take no responsibility at all and call it having boundaries.
Paul does something braver than either. He places the weight of your obligation on the part you can actually control, and he releases you from the part you cannot. You are answerable for your own willingness. You are not answerable for someone else’s. That is a far lighter load than the one most people carry, and it is the one God actually assigned you.