Richard Smoley, from the last video, looks at the topic of radical forgiveness. Forgiveness is a key topic within Christianity, and it is the practice at the heart of A Course in Miracles. The idea behind forgiveness is that one does it for one's self. You don't forgive the other person to give the other person something, you forgive the other person because you have created an image of the other person in your mind that is eating away at your peace. To cure your own distress you must cure that mental impression.
At the same time forgiveness does not mean to become a doormat. Remember, Jesus overturned the tables at the temple and he whipped the money changers. Jesus instructed his followers to "Sell your cloak to buy a sword." You shouldn't leave yourself defenseless, nor should you let someone off the hook who is abusing you. We are instructed multiple times to avoid toxic people.