Ancestor Worship/Veneration
Ancestor worship and veneration is the belief that one’s ancestors stay on after death and can interact with the world as a whole. Ancestor worship can trace its ancestry (ha-ha) back to the origins of humanity when people were first shown signs of reverence in burial practices. The belief of ancestor veneration is a common theme throughout nearly all ancient cultures and many modern day cultures. Ancestor worship is commonly headed up by a family elder rather than a setup church and oftentimes there are little shrines in homes that you can pray at. While it is considered a belief system you can still hold another belief system while venerating ancestors this is often a choice because people like the personal connection they get from their ancestors
Modern ancestor worship practices differ very little from their original forms except for in cultures where the practices were banned or outlawed like in Mexico where the practices of ancestor veneration were converted into the holiday day of the dead. But even then it is a widespread informal timeless belief system that has held on for thousands of years.
Ancestor worship has for millennia existed in nearly the exact same form even with major interference from many other religions. This is entirely because of the lack of size and organization ancestor worship as a religion was very personal and you weren’t going to see a church of ancestor. This is important because when you are organized into a bureaucracy it is often subject to human ambition thus the disorganization allowed it to keep with its founding principles because there was no need to take power because they were in small disorganized groups that wanted to keep it that way. They also integrated rather well with other belief systems for example in Mexico when Christianity came along and banned any native religion it simply built itself into Christianity as the day of the dead. In Asia you can be any sort of religion and still hold your ancestors in high regard this is because of its disorganization and lack of size since it wasn’t perceived as a threat people were allowed to keep it around.