Alright everyone I looking for any problems that would occur from a player creating a religion in game. For example let us say an evil party comes to town and one character walks up to the leader of the town and makes some speak to this leader about how he wishes to establish a church, shrine, or whatever you want to call the place of religious gathering in this town. The character plans to set up the religion of a god he completely made up. The character is from a somewhat distant land that has relatively no contact with the area he is currently in and claims it is a god of his home land. He also plans to use this as a way to amass a following for his own goals. Now if the character takes cleric levels in this "god" what problems should be expected from this. Also I wonder how the divine magic will work since it is a god that does not really exist.
Please do feel free to leave any feed back as it has been quite some time since I created a religion in game and do not remember the repercussions. Any and all help is greatly appreciated.