Much of the pyramid building was tied to ancient Egyptian beliefs about religion and the afterlife. Egyptians believed that their rulers were also gods. This belief in many gods is known as polytheism. The Egyptians believed that they needed to please the gods.
Many ceremonies and tributes were made to honor these gods. Many details about their beliefs are seen on sacred scrolls, artwork, and sculpture. As you have read, Egyptians believed that after they died a new life for them began, and this gave them a way to live forever. They traveled to another world in the afterlife and lived with the gods and goddesses of the dead. The mummification process is cleverly drawn and explained together with many facts about the Egyptian belief system and its pantheon of gods led by Ra, the sun god and the god of creation. He was called AmenRa during the Middle Kingdom. Osiris, Isis, Horus, Thoth, and Anubis are lesser gods, yet they all are involved in the lives of the Egyptians.