Better Pantheons is a comprehensive religion overhaul with several basic design goals.
Firstly, the effects of Pantheons have been extended, more opportunities for a given example are available, and pantheon specific structures have been given to every example.
Further, all Pantheons, Founder Beliefs, and Enhancer beliefs have effects and structures designed to generate Faith, as well as one or more other resources; all other Beliefs have been religated to Follower beliefs quite deliberately.
The overall effect is that religion is more complex, and can use a wide variety of effects with multiple synergies.