The Egyptians believed that they would have another life after death. What things in nature may have given them this idea?

Ok this is short and simple unlike the other answer. Things in nature like lets say an animal dies the another one is reborn. So they saw that and thought they thought they had the intentions as the animals.

The Egyptians had complex beliefs about life after death. Death was not considered to be the end of one’s life, rather it was considered to be a necessary process that one has to go through in order to enter a dimension of complete bliss and eternity. However this was dependent on the way the individual lived their lives. The Egyptians have their own criteria for judgment according to which each individual will be judged and awarded his destination in the afterlife. So the sun setting then rising again ...