The Evidence of Things Not Seen

"This didn't exist [when time began]," Cas continues. "Hence, it did not receive a name. Here, the rules must be different, unless…" He pauses, giving Dean a sidelong glance. "Do you remember what I told you when I drew it?"
"Dude, I'm not sure you were even using sentences," he answers, but he tries to remember anyway. "Something about hoped for, uh, the evidence of--unseen?"
"'The evidence of things not seen'," Cas says, looking pleased. "King James Bible, Cambridge Edition. I remember now."

— Castiel and Dean, Map of the World, ch. 3

"I wasn't actually being ironic," he says, fighting to keep his voice calm. "I was very high but not stupid. I knew it the first time I saw you, I just thought it was too late. All things must have a name, Chuck was right, and it did; I named it after you."
For faith is the substance of things hoped for, the evidence of things unseen: six sigils named in honor of an impossible man.

— Castiel, A Thousand Lights in Space, ch. 7