Just an idea: after starting your first main religion you can use another great prophet to start an anti-religion. This would be spread by spies to enemy cities and would hurt their cities. You would pick beliefs like -1 food for rivers or -2 hapiness etc that you could pick to hurt your enemy's cities as much as possible depending on which tiles they have. The enemy would then have to eliminate the religion from their city by inquisitors.
what do you think?
what do you think?