There are no justified resentments. To resent someone is to fall under the illusion that they are the cause of our suffering. No one can die from a snake bite. It’s the poison that kills them. You may receive the poison of another’s words, or even just in a glance, but you don’t have to absorb it or allow it free passage through the veins of your consciousness.
The consequence of not absorbing the poison of others is you never experience enmity towards others. And people notice when you have absolutely no enmity. It draws them close, it empowers them, it builds trust, it enables harmony to break out! It is only because the lion has no thought of killing the lamb that the lamb feels able to come so close.