Sheep are animals living in a herd. Somehow the have the instinct implemented to search "their" shepherd.

And the shepherds (the ticks...) they look up to for "pseudo-security" so to say, "brainwash" them with their own bullshit. Until most of the sheep start to make up many parts of their personal simulation out of the most blatant bullshit their chosen shepherd brainwashes them with. This only can happen, because all these "magic" fairy-tale books like the bible are intentiously kept very vague, so that the next generation of "shepherds" can brainwash the sheep according to new outside parameters of the "general" simulation of "reality" that is labeled to be "en vogue" or "the truth" at that vicinity in time.