Why are cells considered a necessary precursor to life?

A cell is considered as the structural and functional unit of life that is life cannot exist without a cell. It is also considered the basic level of organization of life.

A cell include all the structural components like:

1. Genetic material- which can be inherited,  

2. Organelles- performing specific functions like mitochondria (powerhouse), ER (protein synthesis).  

3. Proteins- which perform metabolism and provide structure to an organism.

4. Cytoskeleton- to provide structural support.

5. Cell membrane- which encloses all these components required for life.

All these structural components work in a coordinated manner to perform various functions from metabolism to energy production.

Thus, a single cell has the ability to start a life.