be-all and end-all

American  

[bee-awl uhnd end-awl] / ˈbiˌɔl ənd ˈɛndˌɔl /

noun

1. the central and all-important part.

   His work was the be-all and end-all of his existence.

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be-all and end-all British  

noun

1. the ultimate aim or justification

   to provide help for others is the be-all and end-all of this group

2. humorous a person or thing considered to be beyond improvement

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Etymology

Origin of be-all and end-all

First recorded in 1595–1605

Example Sentences

It's not the be-all and end-all, but it would be another marker the players can look back on.

From BBC

"I have sometimes felt that snooker is the be-all and end-all, but this has made me realise how lucky I am, and it has freed me up to just enjoy the game."

From BBC

The realization baffled me, since that had been primary on our minds when we left—the be-all and end-all of our journey, the reason for leaving Mamá’s side.

From Literature

For Villarreal, this match is the be-all and end-all, a chance of instant immortality.

From The Guardian

Apparently, Mr. Will’s lessons would feature only cisgender, heterosexual, able-bodied, White men born in America, a dangerously small section of the population to present as the be-all and end-all of humanity and history.

From Washington Post