How do you let someone know that you care about them but they'll be better off without you anyways.

To tell you the truth, a comment like that is terribly lacking, and not very comforting to the recipient. One cannot make up an excuse, because it will only feel to the other person, that it is only meant to make them feel better, when in fact, they will not feel comforted in knowing that you were just trying to make them feel better. Haha if that makes any sense to you. It's more like an oxymoron. "I'm going to leave you, but don't [i]feel bad [/i]because it is actually best for you" type thing. Doesn't work. Not for someone who is hurting. It just feels like an escape route. It's not convincing and you can't tell someone else how to feel about it. It's going to hurt anyway so just be honest and tell the truth. Yes, it is the truth in your eyes, but it won't be felt as truth, to the one who is hurting.