Answer:
Because burial is part of the religious practices of a people, and once you understand their ritual practices, you can learn more about their beliefs.
Step-by-step explanation:
A good example is mummification performed by the Egyptians. The process was made with care and attention to send the Pharao's body and his soul to the other world. When you learn the ritual, and especially the way the pyramids were built (and why), you can understand how Egyptians face death and how they prepare themselves for it.