The Enlightenment, also known as the Age of Reason, was an intellectual and cultural movement in the eighteenth century that emphasized reason over superstition and science over blind faith. Empiricism promotes the idea that knowledge comes from experience and observation of the world.
The Greek gods and goddesses were believed to live on top of Mt. Olympus, the highest mountain in Greece.
The Spanish conquistadors believed them to be infidels. They would read them a note from the Pope in Spanish that they wouldn't understand in which they would proclaim that their land would now be Spanish because Spain is governed by one true God, and after that they would slaughter them if they wouldn't surrender.