User blog comment:Mlgrsd/Will Crowley return from the dead?/@comment-27669262-20170525112654/@comment-1031724-20170528004511

Let's also remember that the resurrection of a demon is unprecedented in Supernatural. Only humans and angels have ever been revived, and angels have only been revived by God. Also, if Lucifer could have revived demons, he'd probably have revived Lilith so she could break the seals again if he ever got reimprisoned. Which he did, and stayed there for five and a half seasons coz Lilith wasn't there to re-release him.

That's not to say it can't be done, coz there are almost no demons God would want to revive.