A fallen angel finds a desperate bloke, intercepts him at the gates of hell and makes him think it's the gates of Heaven. Zachary didn't take your feather, you put it in his hand so you could break through to Earth.

Constantine

Constantine: What happened to you love?
Imogen: I was taking a dying mortal to Heaven. I don't know how, but he pulled a feather from my wing. He was revived, I fell to Earth.
Zed: That must be what I saw in my vision when I touched Zachary.
Constantine: It's the only way an angel can enter our plane in physical form; damage to the wings. One feather, piss poor design if you ask me.
Zed: That's what Zachary has; an angels feather.

Zed: I could feel him John. He was so close to death. I felt what he felt in that moment.
Constantine: An angel so you said. So you get any other sense of Zachary the great and powerful?
Zed: Well, he has good intentions and he's unquestioning in his faith.
Constantine: A bit boring, but okay. Let's say he's not the dark part of this equation.
Zed: Unless he's being manipulated. Blind faith can be a dangerous thing.
Constantine: Spoken from experience.

Constantine: You said snakes?
Zed: Yeah
Constantine: Our training is expanding your psychic awareness. You see there.
Zed: What Kentucky?
Constantine: Middle of bugger all. Seems a preacher was bit by a poisonous snake which explains your vision. He came back to life and started performing miracles. Now he's a bloody star.

Constantine Season 1 Episode 7 Quotes

Constantine: You said snakes?
Zed: Yeah
Constantine: Our training is expanding your psychic awareness. You see there.
Zed: What Kentucky?
Constantine: Middle of bugger all. Seems a preacher was bit by a poisonous snake which explains your vision. He came back to life and started performing miracles. Now he's a bloody star.

Zed: I could feel him John. He was so close to death. I felt what he felt in that moment.
Constantine: An angel so you said. So you get any other sense of Zachary the great and powerful?
Zed: Well, he has good intentions and he's unquestioning in his faith.
Constantine: A bit boring, but okay. Let's say he's not the dark part of this equation.
Zed: Unless he's being manipulated. Blind faith can be a dangerous thing.
Constantine: Spoken from experience.