Be-All And End-All Meaning

(idiomatic) Something considered to be of the utmost importance; something essential or ultimate.

Example:   He thought that cars were the be-all and end-all of life.
  Profit is the be-all and end-all of business.
2014, A teacher, "Choosing a primary school: a teacher's guide for parents", The Guardian, 23 September 2014:
  The compulsory tests in reading, writing and maths at the end of years 2 and 6 are often mistakenly seen as the be-all and end-all of a child's chances in life, and the quality of their school.