I previously discussed religions quite a while ago in my post Language and Religion. However, that was a pretty brief overview, and I would like to expand on the basic names and descriptions, and include some lesser gods as well.
The main religion of Mareten follows Alehim (pronounced Ay-leh-heem), the creator-god. The stricter followers to the faith claim he is the only god, and that any other gods are made up, and/or evil. However, the church generally acknowledges other lawful gods as such, though at a lesser tier - demi-gods, or even angels. Many legends tell of Alehim in his role as creator of the world, though few beyond that; it seems that Alehim only interacts with Mor-Thir through his followers, the clerics, paladins, and blade-dancers. His followers display a rising sun as his symbol.
The men of the southern deserts follow Kai-Ra [kie-rah], god of the sky and winds; Kai-Ra is probably the most fickle of the lawful gods, in legends often leaving his followers to fend for themselves while he dealt with some trouble or another. His symbol is a stream of tan sand on a blue background.
Thor is the lawful god of the dwarves, and ruler of thunder and earth. And trees. And drinking, and... well, let's just say Thor knows how to party. Thor's followers swear that every thunderclap is caused by Thor, and smugly note that they have the most proof of Thor's existence. Thor's symbol is a large hammer.
The True Elves, as well as the Gnomes, worship Danu, the mother goddess. Compared to the lavish cathedrals of Alehim, the devastating winds of Kai-Ra, and the powerful thunder and lightning of Thor, Danu seems quite tame. However, she holds a power over other gods, since she is their mother, and each of them were born from a fragment of her personality; as such, she has a piece of each god, good or evil, inside herself. Her symbol is a Triskelion, or three whorls.
The Fae, rarely, serve Lleu [Hlew], once a mortal king who was uplifted to godhood through his good deeds. His symbol is a silver hand, raised in peace.
Finally, the barbarian tribes of men, as well as the more animalistic tribes, server the Bear, a kind, yet strong creature. In legend, the animal gods are known as "The First" - the Bear is the First Bear, the most powerful of his kind. Its symbol is, obviously, itself.
Mareten serves no neutral gods; those that are neutral either worship other gods, or no god at all.
The men of the desert serve Aladeen, a crafty and cunning opportunist, who in legend not only gains the upper hand over his enemies, but makes fools out of them in the process. His symbol is a lamp.
The dwarves follow Loki, the ultimate trickster; while his actions may seem chaotic, his heart strives for good. Eventually. In the end, his heart and actions, and those of his followers, are decidedly neutral. His symbol is snakes, twisted in knots.
Neutral Fae - usually the Summer Court - serve Gwydion, a precocious prankster, and Llew's uncle, if the legends are true. Though usually kind-hearted, his actions are his own, and not bound by any laws; as such, Gwydion is capable of both gentle love and terrible wrath. His symbol is a prancing pig.
Neutral True Elves and gnomes serve Manannán, god of boats, pranks, and powerful magic; he is known in legend for both healing and necromancy. His symbol is, of course, a boat.
The tribesmen and beasts worship Coyote, likely the most powerful of the neutral gods, whose actions, at least according to legend, brought Alehim to Mor-Thir. His symbol is, of course, a howling coyote.
Though there are no chaotic gods in Mareten, there are a fair number of demons, which I will discuss shortly.
The men of the southern deserts worship Erklik, evil god of the underworld - according to legend, a dark, menacing, snake-like creature, who steals the living and drags them down to the underworld. His symbol is a shooting star.
Dark Dwarves serve Jörmungandr, the evil serpent, destined to eat Thor; its symbol is an ouroboros.
The chaotic human tribes and beasts worship the Serpent, a slithering, vile creature who smells of death. Its symbol is, of course, a snake.
Though few, the dark gnomes and the few evil descendants of the True Elves serve Balor, a suspiciously serpentine one-legged, one-eyed giant whose gaze destroys all life.
The Fae and their ilk serve Ysbaddaden, a terrible serpent.
While the neutral and lawful gods vary, sometimes significantly, the chaotic gods are quite similar, even to the point of having similar myths and legends; a snake, powerful and magical, destined to devour the corresponding lawful god at the end of the universe, and often related to the neutral god. The chaotic god is somehow restrained, be it by choice or circumstance (be it wearing a blindfold like Balor, holding its tail like Jörmungandr, or banished to the underworld like Erklik or Ysbaddaden), and its release signal the beginning of the end.
Demons And Their Ilk
Though Mareten has no recognized neutral or chaotic gods, there are a plethora of different evil near-deities to choose from. Street of the Gods aside, powerful demons from the infernal planes often attempt to be drawn into the world. they generally fall into one of three categories: intelligent, animalistic, and mindless.
Intelligent infernal creatures are shrewd, cunning, and willing to make deals to secure a hold on the world. They are the creatures who will buy a soul, and are the devils so many are willing to make a deal with. They enjoy the "long game", and enjoy weaving complex webs of deceit and destruction. When appearing to men, they have at least a semblance of the human form - cloven hooves, wings, red skin, or otherwise, at least they have the right number of arms, legs, heads, and so on.
Animalistic infernals are no less powerful, but rather than bargain with creatures, they would rather take by force. They are destructive and greedy, preferring short-term bloodbaths over long-term conquests. Less shrewd than their intelligent associates, animalistic demons tend toward monstrous forms of known creatures: enormous boars, giant grasping insects, or inhumanly-muscled men, to name a few.
The final group of infernal creatures is the most dangerous by far. While careful planning can topple kingdoms, and unholy fury can annihilate an army in an instant, the calm, steady destruction of a mindless infernal can undo an entire universe. Even the most base animalistic infernal can be reasoned with; no matter how dense, a certain amount of pain will stop any being. Not so the mindless infernals; they have no more sense of pain than a pile of worms or spiders. They consume out of instinct, and destroy merely because that is what happens when they are near. They have no plans, no joy of destruction, no base desires; they consume because that is what they do. Mindless infernals do not take the form of any recognizable thing. Formed in the outer planes, they form a writhing mass of bones that drip acidic slime, or a throbbing mass of probing tentacles, or a gibbering lump of flesh covered in bloodshot eyes and screaming, drooling mouths.
A Final Note
Take heed that lawful does not mean good, nor does chaotic mean evil; while most lawful gods strive to bless their people, it does not mean that they are, themselves, good. Rather, lawful gods merely wish to build and sustain civilization against uncivilized forces - and that civilization varies wildly between gods. For Thor, it means a booming civilization of iron and industry, while for the Bear, it means a peaceful coexistence with nature, and the two may directly conflict over that.
Neutral gods have no desire to destroy civilization, but neither do they have the inclination to work to uphold it, though they may admire or even assist those who do - as long as it doesn't take too much effort. They can afford to be pranksters, because while their jokes may, in some small way, dismantle civilization, their work is quickly repaired by the hands of the lawful gods and followers. Some demons may even be considered neutral, for they wish to build their base of power, they only grow in power with more followers, and the largest groups of followers take on aspects of some sort of civilization.
Chaotic gods are, however, entirely evil. As a whole, they actively work to tear down civilization, of any kind. Some may do it because it enriches them, others simply because they wish to see the world burn, but all would see the world in chaos.