“I knew then that Jocelyn would never come back to me, because of you. You are the only thing in the world she ever loved more than she loved me. And because of that she hates me. And because of that, I hate the sight of you”
Since he helped raise her as she grew up, Clary grew to see Luke as her true father, as it is shown that she loves him as such, rather than Valentine. This is something she has even said out loud; she does not see Valentine as her father, despite him biologically being so, but rather Luke since he took care of her and took part in raising her as a child, something a real father does.
“Clary, you’re an artist, like your mother. That means you see the world in ways that other people don’t. It’s your gift, to see the beauty and the horror in ordinary things. It doesn’t make you crazy — just different. There’s nothing wrong with being different.”