I think that if the show continued, it would have stuck with the three main characters investigating and stopping whatever "evil" was coming. Paul might have played a crucial role, but that's about it.- A show about the rise and career of the Antichrist.
I second that one.
Miracles might have evolved into that story. I got strong antichrist vibes from Paul - who would be unaware of his own identity. What if Alva Keel suspected who Paul was, and that was the reason he contacted Paul in the first place - to keep an eye on him and see if his fears are realized? Alva's mission may have been to kill Paul.
Same thing. Sam's purpose might have been revealed, but the show would never have been much more than him and his buddies vs. the Devil.On the comic front, Reaper could have evolved into that story, too. The other option, even crazier: Sam's the Second Coming. Morgan could be the antichrist. However, the way they were going, it seemed unlikely that they would get that heavy. They were on the CW after all.
So far, no one has made a modern day series specifically about a central character rising to prominence and influence in accordance with the prophecies about a messiah/antichrist.