The Ark of the Covenant was a device used for communication by members of the 12th Planet. They found the element gold to be useful in many ways, and treated it in a worshipful manner by elevating gold to the status of a god - the god of communication. Crystals have also been so used by this race, as communication boosters. Because of the awe and reverence surrounding the Ark, primitive humans perceived the Ark to be a touchstone of the gods, especially when the voice of what they assumed to be a god came booming forth. Members of the alien group from the 12 Planet would go inside the Covenant, voices would emerge, and then they would leave, having gotten their instructions. Surely this was from God Almighty! The Ark itself was treated as a sacred object, as it was valued and lives were sacrificed if it was mistreated in any way. Like most objects that are poorly understood, but seem magical, the Ark of the Covenant gained a reputation that superseded its true worth. The Ark was eventually broken down and its gold reused, by the folks who built it and understood that it was not at all sacred. Humans, poor misguided souls, are still looking for this lost Ark, and may look forever.