Answer:
The Egyptians constituted an extremely religious society. This religiosity determined cultural and social practices among the Egyptians - one of them was the belief in immortality. For the Egyptians, death would be fleeting and life would return to the body, but the return to life would happen only if the body of the dying man was preserved.
If the soul (Ra) did not return to the body (Ka), it meant that the body had not been preserved. Hence the importance of body mummification, embalming and conservation in order to avoid decomposition. For this there were advanced techniques of mummification for the nobles and simpler techniques for the poor.
The advanced mummification techniques developed in ancient Egypt existed only because of the developed medicine. Egyptian doctors performed surgery, cared for fractures, knew the human anatomy. In addition to the technique of preserving bodies through mummification, the Egyptians needed to develop a method of protecting bodies from looters, hence the construction of huge tombs.
The graves would ensure the conservation of the bodies. Usually when a rich person (pharaoh), who boasted power, died, his body was mummified and later placed in the tombs that were considered a true dwelling. In them, Pharaoh and his riches were buried in a royal chamber and his servants (servants), scribes, priests, and animals in other simpler chambers.
The sacrifice of other people with Pharaoh's death was explained by the belief in immortality - the return to life would mean having other people to serve him (the servants) and continuing his wealth was critical to exercising power.
