Not every reason.

[ Not when Sam had Wynn's faith. Not when Dean had no proof of Sam being this monster, had never seen him do anything but good. She shakes her head. ]

I'm happy that you forgive him for how he was acting. But that's because you know him. I only know what I've seen. [ And what she's seen is not flattering. ] If he wants me to see the good side you seem to believe is in there, he's going to have to show it to me himself.