I may well change my mind when I discover this doesn't work but...
So its a few years in the future and humanity is connected through advanced internet systems.
Religion remains strong, and has grown in many places despite the technology.
However a new heresy is beginning to creep into the system.
People keep saying they have spoken to God on the internet.
Has the ephemeral nature of the net actually found an abstract way to touch heaven?
What is God trying to say?
Why is it that Hebrew characters used in webspace are having almost magical effects?
Your characters are charged with rooting out this heresy,
but as men of faith can they ignore the evidence in from of them?
Thats the basic concept.
I'm toying with it being an Islamic empire as well.
In my world Christianity didn't hold Europe together after the fall of Rome and the Muslims managed to take control.
Hmm, Christian terrorists perhaps? Have to think about that one.