Living things need energy because "cells need energy without energy the cell cannot perform its functions to survive." In result the cells will die and when cells die that's not good for the organism. In conclusion, all living organisms need energy.
Hope this helps.
Explanation:
All living things consist of cells in their bodies. There are trillions of cells in a human body. Cells form the structure of the body. Cells cannot survive on their own, because they continuously need energy to perform different functions of the body of the living things. Functions of living things may include growth, repair, reproduction, movement, etc. So cells take nutrients from the food which a living thing eats, convert those nutrients into energy and then use that energy to perform the above mentioned tasks. So Energy is needed by all living things to stay alive.
