ancestor veneration or communication. not worship.
ancestors are not gods, but as spirits they have powers and look after their families & descendents.
spiritually you are of your ancestral energy, ancestors live on through their descendents. reincarnation is within ones descendents. the body is a shell for the spirit. the spiritual identity of an individual continues on after death for a while, thus, sacrifices, offerings and communication is done with the ancestors. this nourishes and strengthens that ancestral energy.
this is a universal practice in african religions.
the old testament forbids communicating with spirits; the old testament undermines ancestral communication.
yahweh, el...these "gods" act more like a deified community ancestor, or a tribal deity as these hebrew gods have a "chosen" people. wouldn't the supreme ancestor be universal? why have a chosen people?
ausar in kemet is basically a deified ancestor; understanding reincarnation, the kings would identify with ausar (their ancestor); and also by identifying with the oneness of god they would die in the right frame of mind to prevent reincarnation. the pert em heru & pyramid/coffin text spells were so the spirit of the king would see his likeness on the tombs, his possessions, and read and remember the spells written on walls and papyrus and this would aid in the spiritual journey into the afterlife and to the path that avoids return and reincarnation.
mummification, the "spells", the union between heru & ausar, these are all the same basic spiritual principles that ancestor communication is based on. it's understanding death, the spirit, and communicating with, nourishing, and aiding the spirit during that transition.
now we can study which religions preserve this knowledge of death and the spirit, and which undermine this knowledge.