I found an awesome use for my free great general though, settle near a city state which had el dorado. El dorado is now mine with +4 faith, and there were truffles nearby too.
Also one of the AI made a religion with desert folklore and monasteries. I spread it to my desert and wine cities asap, and want to try get the monasteries in all my cities too, gonna need a heck of a lot of missionaries, but I have loads of faith.