Pantheon:
Fertility rites is extremely strong, one of the best of all beliefs, let alone pantheon beliefs. At 15% it would still be very good. Still decent at 10%.
Oral tradition is strong, it affects too many different tiles (bananas, sugar, dyes, cotton, wine, incense,
Earth mother is weak, copper and iron are rare, though salt can sometimes cluster. Add gold and silver maybe?
God-King is weak.
Messenger of the gods feels fairly weak.
Religious idols seems weaker than most because gold and silver rarely cluster, unlike many other luxuries.
Stone circles is a bit weak: marble is rare and doesn't cluster, stone is fairly rare.
Founder:
My main complaint is that founder beliefs should be the most powerful beliefs, and should all (or nearly all) reward you for having a widely spread religion, either to many citizens, to many cities, to many foreign citizens/cities, or similar. Many of the beliefs here don't belong as founder beliefs, and some that do belong as founder beliefs aren't here.
Charitable missions doesn't belong here (it's a good follower belief).
Holy order doesn't belong here, and is very weak as a belief in general.
Initiation rites feels a bit weak but I haven't really used it.
Interfaith dialog just feels like a dud policy, too hard to use, and weak.
Messiah feels weak and doesn't belong as a founder belief.
None of them really feel strong - when they should be, these are the rewards for religious founding.
Follower beliefs:
Many of the things which should be follower beliefs are not, and some things that are follower beliefs should be elsewhere.
Choral music is too strong. We're adding too much culture in general to the mod, which makes tourism too hard, and devalues culture in general by making it too easy to get.
Feed the world is much too strong.
Sacred sites is potentially strong, but doesn't feel like it works as a follower belief: this would be a good, specialized reformation belief.
Swords into ploughshares is good, but mostly because it's very easy to avoid war at the moment.
Heathen conversion seems weak to me in general, though I know some people have found it useful.
Holy warriors is great in concept but the pre-industrial is frustrating. Could it be pre-modern, at least?
Enhancer beliefs:
Overall most enhancer beliefs seem fairly weak: just war, itinerant preachers, religious texts, religious unity and reliquary seem like the only ones ever worth taking.
Just war is too strong: you basically quadrupled the value of these beliefs by combining the offensive/defensive and doubling the bonus. I'd revert to 20% bonus then it's probably fine.
Evangelism seems weak but I've never really used it.
Underground sect seems incredibly weak.
Unity of the prophets seems fairly weak, but I've never used it.
Reformation beliefs:
Many of the things which should be follower beliefs are here. It's weird to put so many generally useful beliefs into requiring the entire Piety tree.
In my view reformation beliefs should be about either boosting the overall value of having a widely spread religion (like founder beliefs), or should help you to turn religion to support a particular victory condition or specialist playstyle (city states, tourism, tall, wide, conquest, etc.).
Cathedrals, pagodas, mosques should be follower beliefs.
Courage, Jesuit education, thrift, Religious fervor, work ethic seem fine - though jesuit education is probably the strongest of these (more important expensive late-game buildings that you want in lots of places).
To the Glory of God seems a bit narrow.