The Levites were the priest class. They knew all the secrets and took advantage of their inside information.
The priests were some of the earliest advisors of the kings. They were the earliest society of intelligence. They taught the children, they knew all the secrets. They used that information to manipulate the kings and eventually corrupt them to suit their needs.
You think the priests of Christianity didn't use the information learned in confessions?
The Vatican today is just a giant information warehouse.
>They served God.
They served themselves just like everyone has done since the dawn of time.