Eckhart Tolle argues forgiveness is unnecessary because harmful actions come from unconsciousness, not someone's true self. When people hurt others, they're operating at their highest available consciousness level and unaware of what they're doing. There's nothing to forgive because the act doesn't reflect who they actually are.
Chapters
When Eckhart Tolle is asked about forgiveness, he says that you don't actually need to forgive. You don't need to ask for forgiveness. You don't need to give forgiveness. You wanna know why? This is the crazy thing. He says that anything that happened happened from a certain level of unconsciousness. So remember this, you're always doing the best you can with the level of consciousness you are at. So when someone else in your past did something wrong to you, they did it from a level of unconsciousness. They weren't aware of what they were doing. So because of that, at the deeper core level, that person is a divine being. It wasn't the person's level of deep presence that did it to you. It was the aspect of themselves that was unconscious. And once you realize that, that's what Eckhart Tolle means when he says there's nothing to forgive because what that person did wasn't their true divine self. It was the unconsciousness within them that you're actually forgiving.