"Agape's Manhattan Project : Why ten billion of us ultimately benefited when a dying Manhattan doctor put saving ten others above his own live"

This sub-title at least avoids the dreaded "XX : How .." phrase.

"Agape's Manhattan Project : How ten billion of us benefited when a dying Manhattan doctor put saving ten others above his own life"

This possible sub-title is much more conventional - breathlessly banal even.

Along the lines of "XXX: how the invention of trivial-seeming Y  actually changed our whole world for the better forever !!!

And even more customer oriented --- note the word 'benefited' !

Every book proposal always has to say how the potential book customer is to benefit from purchasing it, literary agents and editors tell every would be nonfiction author.

Agape's Manhattan Project : A lapsed Calvinist on a catholic mission - 'penicillin for ALL humanity'

This subtitle is very character oriented -  clearly its about Henry Dawson, the chief protagonist .

My other subtitle is customer-oriented ,being about us , the potential reader (Agape's Manhattan Project : Ten billion of us, our lives improved , because a dying doctor put the saving of ten others' lives above his own).

"Agape's Manhattan Project : Ten billion of us, better off , because a dying Manhattan doctor put saving ten lives above his own"

Or :

             "Agape's Manhattan Project" 
Ten billion of us, our lives improved ,because a dying doctor put the saving of ten others' lives above his own

a possible sub-title for "Agape's Manhattan Project" ?

Agape's Manhattan Project:

Ten billion of us since 1940, better off , because a dying Manhattan doctor putting saving ten others' lives above saving his own...

Inspired by J Hamel and S Mosher

 Like Henry, J Hamel was much too eager to step in - when she was needed.

S Mosher was an eloquent spokeswoman for the very small while this work was being written.

Those are the dedications, the elevator pitch, in one sentence, is this :

"AGAPE'S MANHATTAN PROJECT" is about us, all ten billion of us, who have indirectly benefited from a selfless act of Agape -- a dying Manhattan doctor's project to put the saving of ten of his fellow beings above saving his own life....

Agape for non-believers : its all that soppy 'Corinthian talk' at church weddings

Particularly all that stuff about  "faith, hope and charity but the greatest of these is love" that always gets so many of the wedding congregation barely sniffing back tears.

Never been to a church wedding ? Spent your live in jail ?

Well then how about that Alan Jackson country song about 9/11 , "Where were you when the world stopped turning..." - for years, it was hard to avoid hearing it, particularly if you resided in prison.