The Ancient Egyptians believed that when a person dies, the dead person's body's spirit and soul leaves their body. However, the spirit/soul could return to his/her if he/her wants to live forever. So the Ancient Egyptians mummify the body so that the spirit/soul can find their body.

Why

The mummification process is believed to have originated from the burial of the Old Kingdom rulers at about 2600 BCE.

Mummify?

The Origin of Mummification

Sphinx

Great Pyramid of Giza