It's actually pretty simple: Ancient people were just plain superstitious and ignorant.
Or in other words: they were very stupid.
- They believed that "sacrafice would please god.. (maybe make it rain?)" Can you imagine your zerglings pulling this shit? I'd delete them immediately for being so freaking wasteful and stupid! (Apparently stupid people thought god had a nose sniffing around on earth and he "liked the smell" of burning flesh. Pretty weird stuff.)
- They believed in "dragons"- becuase they were ignorant and stupid.
- They believed in a "chosen one" - again, because they were ignorant and stupid.
It's fun, really. Imagine playing Age of Empires and your empire is the ancient Jews.... Everytime you get a shipment of food, they burn half of it to keep you happy and the dragon away! Wouldn't that make you happy?
- Lime