My current face-to-face game is running without specific deities. Still, the cultures of most regions include some form of faith and religious behaviour - but such preach moreos about being good to your neighbors, raise your family properly, et cetera. Evil clerics, when organized, are more like cults than organized churches.
In fact, churches and temples are moreso political organizations, community leaders, and general care-takers. Any person can freely worship in any church/temple, so long as they bring no harm to others inside the church building and surrounding area.
Still, there are plenty of areas where specific domains are common amongst the clerics - the now freed elves of the long-enslaved Elven Forest generally have the Plant and Sun domains - the perpetual twilight during their enslavement by undead has whithered their forest, and the clerics strive to repair that damage.
In fact, churches and temples are moreso political organizations, community leaders, and general care-takers. Any person can freely worship in any church/temple, so long as they bring no harm to others inside the church building and surrounding area.
Still, there are plenty of areas where specific domains are common amongst the clerics - the now freed elves of the long-enslaved Elven Forest generally have the Plant and Sun domains - the perpetual twilight during their enslavement by undead has whithered their forest, and the clerics strive to repair that damage.