Didn't Zacharih say in the season 4 finale the angels were stepping back to allow the demons to take control. He said eventully light (the goodies) would win out and the world would have peace again

Watch Lucifer Rising (the S4 season finale). Zachariah flat out says that he and the other angels in charge wanted the apocalypse to happen. What they want is to kill Lucifer for good and then have Paradise on Earth. Which means that Earth(as we know it) must be destroyed in order to make way for Paradise.
Zachariah is the one who called Sam and (pretending to be Dean)left that vicious message, telling Sam that he was a monster. He kept Sam and Dean apart so that Dean couldn't stop Sam from killing Lilith.

Zachariah: "Lilith is going to break the final seal. Fait accompli at this point. Train's left the station."
Dean: "But me and Sam, we can stop....You don't want to stop it do you?"
Zachariah: "Nope. Never did. The end is nigh. The apocalypse is coming, kiddo, to a theater near you."

I saw that episode, I guess I missed it or something? Wow I'm not very attentive. Thankyou.

You're welcome! :) Yeah- Zach pretty much confesses that he's been lying to Dean all along in that scene. I've watched it manymanymany times! lol It's one of my favourite episodes.