In Black & White Edit
The game takes place at Eden, a peaceful, utopic world without the need for gods. When a kid goes to a beach and runs to the shark-infested waters however, his desperate parents pray to the heavens for help. That sole prayer creates the player's character, which travels at blinding speed to Eden, saving their son just in time.
The grateful family invites the player to their village, where they will be worshipped as a god. The player is then introduced to their conscience: two entities that represent good and evil and help the player learning about their powers and making important decisions. Upon reaching the village, the player is asked for help in finish building their temple, which is the center of a god's power.
Once the temple has been completed, the player is introcuced to Sable, an elder villager that is also a trainer of creatures. Since every god must have a creature, Sable offers the player to choose one, provided they can open big wooden gate in the village. The player accomplishes this after a few small tasks and claims a creature.
Sable instructs the player on basic creature training and departs telling the story of a giant creature that supposedly roams the land, hiding from humans and living alone.
The player finds this creature, who introduces himself as "The Guide" and tells his tale: he once belonged to Nemesis, the most powerful god on Eden, but was abandoned for "not being good enough for him" and had been living alone ever since. He decides to help the player and their creature in return of their friendship. The creature teaches the player what he knows, leaving the most important (and most dangerous) lesson for last: the secret of the Creeds. Nemesis shows up before The Guide can explain this secret to the player, so he urges the player to find three aligned parts of the creed as well as an ally to help in the battle against Nemesis, who wants to be the one true god by destroying every other god and creature on Eden.
Nemesis kills The Guide for his betrayal and proceeds to destroy the player's village, who is forced to escape with his creature and remaining followers through a mysterious vortex.
The vortex takes the player to a new land of Eden, where they are greeted by Khazar: another god who created the vortex to save the player from Nemesis. He helps the player rebuild their realm and teaches them about woshipping, gestures and miracles, among other things in return for help in his own fight against Lethys: yet another god and an ally of Nemesis.
The player starts to gain a clear advantage on this war, converting villages to their cause and approaching Lethys' realm, when Nemesis returns: This time he berates Lethys for his failure, and uses the power of three combined creeds to destroy Khazar and his creature, which is revealed to contain a part of the creed, which Lethys' own creature steals. The player then realizes what must be done: they must obtain three parts of the creed to destroy Nemesis before he does the same to the player.
The player tries to attack Lethys to recover the lost part of the creed, but he steals the player's creature and escape through a vortex. The player follows him to his land, where they find out that Lethys has used some sort of power to bind the creature to three magical pillars, where it is being tortured by Lethys' own creature.
The player attacks and converts Lethys' villages one by one; each removing one of the pillars until the creature is freed. Faced with imminent destruction, Lethys has no choice but to surrender: in return for his own safety, he returns the stolen creed and opens a vortex to a land that contains yet another part of the creed. The player is then given the choice of destroying or sparing Lethys. Regardless of the outcome, the player travels to the new land.
Upon arriving at this land, the player realizes that this is their old realm, the one they were forced to flee from when Nemesis attacked. The land is now in ruins, with fireballs and lightning raining down from the blood red sky. A villager explains that all these troubles were caused by Nemesis, who abandoned this land, but left guardian stones behind: these powerful artifacts keep the land forever cursed. The player is asked to destroy these artifacts. The player complies, but the villager says that one more area must be saved from Nemesis' curse: a lone village that refused to bow to Nemesis, and were punished with a curse of undeath.
After the player heals the village back to normal, the grateful villagers reveal the location of the second part of the creed, which is within the remains of The Guide.
Nemesis returns yet again, telling the player that the parts of the creed are useless without the third one, and challenges them to a duel on his realm, as they and Nemesis are the only gods left on Eden.
The player travels through the vortex to Nemesis' realm, where he immediately curses the player's creature, making its alignment the opposite of that of the player, shrinking it and sapping its strength.
With the help of an informant, the player is able to decurse his creature as well as take all of Nemesis' villages.
The enraged god then mocks the player's creature, calling it weak, and makes his own creature the opposite of that of the player. The player's creature battles and defeats Nemesis' creature, allowing its owner to use the power of three creeds (the third one revealed to be inside the player's own creature) to destroy Nemesis once and for all, becoming the one true god.
In Black & White 2 Edit
Contrary to first observation, the player god isn't the same in the second game as in the first. The first god, despite being the youngest of the gods quickly rises to become the most powerful of them. The first god is able to utilise a vast array of powers and miracles and is able to overpower their fellow divines through sheer power of will and a display of skill. On top of that their creature is vastly more powerful than that of the second god, arguably larger in size, stronger, able to cast greater miracles although having to take time to actually cast them and not to mention better in a fight.
The second god in comparison is far weaker, only able to cast a poor array of miracles and isn't strong enough to simply spread belief of themselves to even the smallest of villages. Instead, this god has to use its followers as its main tools, using them to build a great city and use this as a staging point against their mortal enemies. Though the second god may have a much weaker control of miracles they do however seem to have a greater level of influence upon the world, they seem physically stronger, being able to lift much heavier things than any other god could, not to mention being able to lift multiple things at once and of course able to control the flow of time itself.
It should also be noted that simple origin prevents the two from being the same being, the first god is a Norse god, being summoned after a great deal of preparation and then one pure prayer from desperate parents. The second however is a Greek god, and frequently referred to as such, and also only summoned by the suffering of their people and a single pure prayer, though why the god awakens on the last refuge of the Egyptians isn't exactly explained considering all other gods are shown to awaken at the point of pure prayer.