Outcast is a story of demonic possession and the haunting of one man, Kyle Barnes. Barnes has been followed by demons his entire life, resulting in a reputation around town as a child abuser and wife batterer, so you can understand why he is reluctant to help when a priest comes to him for his help.
The same priest who helped Kyle as a child needs help with the exorcism of a demon in another local boy, and that is our introduction as readers to the history of Kyle's relationship with the supernatural. This issue sets the stage for what, so far, appears to be an interesting story set in rural West Virginia, where religion is deeply rooted in the local population's lives, and even deeper in Kyle's, but not in quite the same way.
This is an extremely tough genre to stand out in, because historically, outside of The Exorcist, fictional stories that focus on exorcism and human possession tend to rely heavily on common tropes, retellings of familiar stories and/or relying on people's already held systems of belief.
With that being said, Robert Kirkman is a man who holds a position of trust amongst many comic readers thanks to The Walking Dead, and that reputation alone led to massive sales of this first issue, and will likely carry a portion of that audience onward with this title based on loyalty alone. Not to take anything away from this issue, which was pretty good, but lets hope that Kirkman can lend a much-needed fresh perspective on this very tired genre of fiction.