Ry Kuntze (hydrokodone@hotmail.com) writes:
...the Forerunner genetically created the Covenant to serve as a militaristic race that would defend the various Halo installations from invasion. To further the Covenant's success, the Forerunner imbued a certain amount of 'holiness' to the Halo structures and fed such truths to the Covenant as a form of religion: if the Covenant believe that the Halo installations are holy, they'll defend them much better.