While this could be an extensive series of articles in itself, and eventually will be for, now its just a overview of everything religious and how it will be dealt with in Aerinwohl and with the Pathfinder rules.
Aerinwohl has been severed from the conduits to the outer planes through the sacrifice of Illshanafiir at the end of the Devil War (I might rename that to the Incursion, sounds better). With his death, arcane and deific energy tore through the portal network connecting portals to each other and to the outside planes. Where there were gates and pathways leading to the various realms, the backlash burned the mystic energies and left a scar. This scar was thick and strong, too great for new magic to pierce through, thus cutting off the world from the Outer Planes.
While the end goal of removing the devil threat succeeded, there was a greater problem with the other gods. Those that resided on the Outer Planes could no longer contact their priests, no longer bestow spells, and no longer guide them. The only remaining gods where those that had avatars on Aerinwohl at the time of the Incursion. Some were there to help their worshippers fight the devils, some were there because they had always been, and others were not yet born. Even those few that had avatars present, without their conduit to their full power, they became weaker, lost part of their portfolio, and their ability to grant spells diminished. Many of these gods died outright, their lesser essence destroyed by mere mortals. Others found a new way to power their might. The end result was the ascension of the New Gods, and a birth of a whole new religion.
These New Gods found power elsewhere, without the Outer Planes to feed them. Some linked themselves to the parallel planes of Light and Shadow. These realms had always existed in conjunction with Aerinwohl and represented twisted versions of the physical world.
The Light is a realm of pure life, uncontrolled and relentless. This may seem fine for mortals, but the overbearing presence of pure life force, and the burning radiance of the sky make it nearly inhospitable for most. It is life supreme and will overfill and destroy most vessels. The Light resembles the physical world, but everything is more grand. Light shines brighter, trees grow to the sky, and creatures seem to be everywhere.
Shadow, on the other hand, is a realm of darkness and undeath. Life does not exist here for long and most living creatures here for more than a few days succumb to the sickness and rise as undead. The landscape is a twisted version of the real world, with broken castles where intact ones stand, the mountains more looming and jagged, the water sickening and rank. The very presence of life brings the undead out in force, searching for meals to fulfill their unending hunger.
Along with the severing of the Outer Plane connection, there was a problem with the souls of the dead. While formerly, the dead would go through the Astral plane to the plane with their alignment, they could no longer break through that barrier. And so, as more and more died from the aftermath of the Incursion and eventually just from normal causes, there was a buildup of souls. They were drawn to the barrier, seeking eternal rest with their deity, but found nothing. They were trapped in a void, between life and death, but unable to understand why.
Thus was born the Collective. All the souls eventually merged into one entity creating a new deity of death and the dead. It held the cumulative knowledge of the souls combined into one confused and frightened individual aspect. While few venerate the Collective, all know that eventually they will die and join it. The Collective does not take on clerics or worshippers, but a few cults have sprung up to praise it anyway. While some may dedicate themselves to death and the Collective, they will never receive its blessing or spells.
And so the New Gods, the gods that remain, and forces that take worship.
First off is the dead god Illshanafiir. While he is obviously gone and can no longer grant spells or abilities, there are still many elves that worship the idea of Illshanafiir and still temples dedicated to his memory. However, as he is dead, they cannot receive spells or any other benefit. The religion has fallen into cult status with shrines in his honor, but acceptance that he is gone. Because of this, many refer to the high elves as the Godless. Very few have taken up worship of other deities, seeing it as an affront to their heritage. There are some who still hope he has somehow survived and will return, but this is unlikely.
The gnomes and halflings formerly had a guardian deity called Tiddlestin. During the Incursion, she was present in avatar form on Aerinwohl, helping her people battle back the devils they had unleashed on the world. With the death of Illshanafiir and the formation of the barrier, she found herself trapped, still aware of who she was, but no longer part of her whole being. She struggled to grant spells to her clerics, but was too weak to save them all. When Mythkael killed the last gnome, Tiddlestin went mad. In a rage, she lashed out at Mythkael and his followers, cursing them and inadvertently fueling his ascension to godhood. She created the drow, made a new demigod, and lost her sanity completely. Her anger also broke the minds of many of her remaining halfling followers, subjecting them to the same insanity she bore herself. They fell in barbarism and chaos, becoming the feral halflings. She retreated into the maelstrom that exists beyond the stars and hides there to this day. The Mad God has some followers, mostly halflings, but also other agents of chaos. There is no dedicated or reliable church, as each attempt seems to fall to bickering and infighting due to the chaotic nature of her followers. Clerics to the Mad God are always chaotic, usually neutral or evil, and spend their time wreaking havoc on the world in order to bring it into resemblance of the Place Beyond the Stars.
The dwarves had a deity of their own named Thurin. He was not present when the barrier rose and all clerics to him lost their connection. The dwarves thought they too were now godless, but a few decades later, a new prophet stumbled into dwarven consciousness. His name was Rurik, and he preached the unity of the dwarves under a new religion, with him as their leader. Many followed the charismatic, but unusually tall dwarf, teaching his words of wisdom and spreading the knowledge of his coming. He claimed to have been fathered by Thurin before the Incursion and most of the dwarves believed him. It was, in fact, true. Thurin was his father, he had the blood of a god in him, and through great trials, he soon rose to be a demigod of the dwarves and their sole religious leader. There was one slight problem though, even though Rurik was the son of their deity, his mother was human. For most dwarves, this was as big an insult as could be imagined. How could their god, the great smith, have a child with a human? There was a split between the dwarves, those who refused to accept Rurik as their patron, and those that chose to follow him as their new god. The split remains to this day, dividing family, clan, and stronghold. Rurik has nonetheless grown in power as the Merchant Lord, the one who determines all trade, all value, and all profit. His wisdom and teachings have led many dwarves to rich lives, while those who ignore him struggle in anger. Rurik’s priests are well dressed, often wearing jewelry of gold and gems. The church itself is extremely wealthy and sends out many paladins on missions to secure trade routes and protect dwarven information brokers.
Nessyk is a being that exists now as it always has. Nessyk has no form, few priests and worshippers, and a scant few shrines scattered across the world with no known temples. Within all living creatures, sentient or not, plant or animal, Nessyk exists. Nessyk is life, and through dominance of strength and overcoming problems, life will always prevail. While clerics to Nessyk are rare, most psions understand that when they tap into their psychic abilities, they are tapping into that part of Nessyk that exists within them. By reaching out to others and their environment, they can fuel more power into themselves. As long as life exists, so too will Nessyk.
One of the few remaining gods of any power is the righteous Jho’shikkur. Extreme in his methods and teachings, Jho’shikkur leads his followers through darkness with the gift of pure existence on the other side. He promotes combat and is dedicated to the destruction of evil, wherever it be found. His symbol is the sun, and his paladins wear armor turned white with an enameled sun of yellow and red on the breastplate. There are many clerics to him, and a solid church in most human cities with great cathedrals built in his honor. The Empyrean Flame of Jho’shikkur is the militant arm of the church and regularly sends out missions to destroy any evil encampments of humanoids, especially hobgoblins in the north and orcs in the south. With the rise of Mikabrun, the warriors have a new front to battle on as they seek to destroy all the undead with the borders. Priests of Jho’shikkur are never subtle or hidden. They are manipulative, sly, and will do all they can to convert more followers to their god.
Out in the raging sea and along the coasts, the power of Selaine is revered. Never much concerned with the matters of the surface world, Selaine was slumbering in her deep ocean cavern home when the barrier was raised. The breaking of her connection to the outer planes was extreme and brought her attention to the surface. She quickly found a way to connect to the plane of Water as well as the Light and Shadow, thus protecting her people and providing them their spells. Selaine is worshipped by nearly every underwater being, as well as paid tribute to by sailors and coastal residents. Her alignment is normally neutral, as she cares little for anything other than the protection of the oceans, but when her rage is turned, she can attack vessels or cities in the form of a kraken. The balance of the ecosystem is her main concern, and overfishing, pollution, or hunting the helpless will bring her wrath. There is usually a low level cleric of Selaine on any ocean ship, as with a shrine to her in the towns near the coast, but very few on the surface actually worship her. It is more those living beneath the surface that venerate her, such as merfolk, sahuagin, and even aboleth.
To the south in the desert region controlled by the orc Horde, priests pray to the Horde Father Gulgac for guidance and strength in battle. While unknown to most of the world, the orcs were heavily besieged during the Incursion and Gulgac took form to help battle them back. He appears as a large, heavily muscled orc, usually in full armor and wielding an axe in one hand and a sword in the other. Nearly all orcs praise the Horde Father, and even many barbarians not born as orcs worship him for his strength and ferocity. Gulgac preaches the power of the orc race and promises a future where they will reign supreme and spread the Horde across the globe. While chaotic, Gulgac has still taught the orcs through his clerics of the wisdom of building towns and encampments, structuring their armies, and agriculture to sustain their demands as they increase in size and power.
The final deity of note is a newcomer to the scene: the demigod Mythkael, Gnome Slayer. Born of an infusion of devilish and deific might, Mythkael was thrust into godhood when he killed the last remaining gnome on Aerinwohl. The Mad God turned his followers into the first drow and gave him an instant base of worship. His body had already begun to transform before his rise, and now he appears as a damaged elf with black skin, burning eyes, large devilish wings, and spikes about his body, running down his spine and across his forearms. He is now a god of revenge, magic, and the drow. While some on the surface worship him in back alleys or pray to him for help taking down an enemy, most of his power lies in the Night Below with the drow. It is unknown where his unholy citadel resides exactly, but it is somewhere in the Night Below on a nexus of ley lines. From there, he rules the drow, directing their machinations and making plans for the take over of the surface and destruction of the remaining races. His clerics are highly regarded in drow cities and they perform both religious and administrative duties. While the Gnome Slayer may never show himself in public, his presence is always felt.
There are a few other minor deities but none that require note here. Cults frequently arise that worship some individual, whether ancestor or powerful in their field, and occasionally, one of them will be raised to demigodhood, but most often these cults lead nowhere. Most towns and villages will have a shrine to an exalted defender or leader, and occasionally these individuals can break free from the Collective and become a small power in their own right, but this is rare. Most often, they are worshipped for a few years, then lose followers and rejoin the Collective.
Druids and oracles do not worship a deity, and thus have no organized religion. Most druids, however, do understand that Nessyk controls all life, and pay attention to it and the patterns it weaves in nature, both or spellcasting and prophetic abilities. It is unknown where oracles get their power from, but it is probably some aspect of the Collective, a small group within the larger whole that has managed a little bit of independence and the ability grant spells.
The final type of cleric is the elementalist. Through a bond with Air, Fire, Water, or Earth, they are able to cast spells of a similar nature as religious clerics, though they always have an elemental twist. When using a healing spell, a Fire cleric will burn the wound, cauterizing and healing it, while a Water cleric will pour water over it, cooling and stitching it back together. The elementalists seek to erase the damage that has been done to the world because of the Incursion, Magehunt, and frequent skyfalls. While air and earth, and fire and water, are opposed to one another, they still all seek balance of the elements and restoration of the world. There are not organized churches to the elements, though there are shrines dedicated to the purest form of them, such as volcanoes, high mountain tops, deep reaches of the sea, or veins of pure metal. Clerics of the elements are found and trained by a single established cleric, going through a trial or test to bond with their chosen element and seek aid.