Any form of media used to convince people of something is called

I believe the answer is: Propaganda

The purpose of such action is to modify people's belief on a certain situation so we could behave a certain way.
The use of propaganda is usually being funded by a certain establishment that would benefit from a certain condition that being advocated in the propaganda.

The  government  of ancient  egypt  was a theocratic monarchy as the king ruled by a mandate from the gods, initially was seen as an intermediary between human beings and the divine, and was supposed to represent the gods' will through the laws passed and policies approved