Final answer:
Animism is the term that describes the belief in spiritual essence in all living and non-living things, representing one of the earliest forms of religious practice.
Step-by-step explanation:
The term used to describe the idea that spiritual power and sacred spirits could be found in all living and inanimate things is Animism. Animism is a religious belief that attributes a spiritual essence to animals, plants, inanimate objects, and natural phenomena.
It is considered one of the earliest forms of religious practice theorized by Sir Edward Burnett Tylor and is often associated with shamanistic traditions. Animism posits a world where everything is interconnected through spiritual agency, from rocks and trees to weather and natural elements.