Origin

The religion which the Ori wish to impose on all sentient beings is called Origin, or the Path of Origin, and it is their way to assert dominance by promising to guide humanity towards enlightenment (i.e. Ascension). Its central promises are supposedly false, and is nothing more than a way to garner worshippers, which in turn increases the power of the Ori. To grant Ascension to all their followers would mean sharing their power, an idea the Ori find less than appealing. Followers of the faith receive nothing whatsoever from the Ori. 
It is a dogmatic, proselytizing faith, which comes with a holy book called The Book of Origin, and specialised missionaries called Priors, enhanced humans who are thus able to demonstrate some of the Ori's powers. Priors are responsible for spreading the Word of Origin, and only designate a people for destruction if they deny Origin outright. The Book of Origin contains tales of how the followers of the Ori returned to the path to enlightenment, and thus achieved Ascension.
The centre of the faith is the city of Celestis (also 'The Plains of Celestis': "The City of the Gods", according to the faithful), which apparently can only be reached by Ring Transporter or by a sort of mental teleportation which leaves the transported individual's body in the same place but brings their consciousness into the city. 
The Ori keep human followers at a low level of development, on par with the Medieval period of English history. They use their powers to maintain a level of fear among the population, who worship the Ori as gods. Among the population of natives to the Ori home galaxy are a group of heretics who believe they are being suppressed, and seek to discover forbidden historical knowledge to show others that the Ori are, though powerful, not gods. These people are in a plight similar to that which the Jaffa were in. Individuals who show signs of doubt for the faith are deemed to be under the control of demons and are said to be "overcome". They are put through a Trial by Fire. It is only through the intervention of a Prior that anyone can escape this ordeal.
--Shaba 04:32 4 October 2006 (PST)