“Find something worth dying for, and/then live for it” is an inspirational saying that has been printed on many images.“Find something worth dying for. Then fervently live for it” was apparently printed in a 1983 book. (The Google Books date may be incorrect.)
 
The saying became popular in the 2000s and was printed in The Arizona Republic (Phoenix, AZ) in 2005, Authorship is unknown.
 
 
Google Books
Merrimac:
140 Years of Ferry Tales ‘Et Cetera
By Char Olson
Merrimac, WI: C. Olson
1983
Pg. 80:
Find something worth dying for. Then fervently live for it.
 
Google Books
Walk through Paradise
By Nicole Walstrum
Owings Mills, MD: National Library of Poetry
1995 (The Google Books date may be incorrect.—ed.)
Pg. 656:
SIENKO, BRENDA
[b.] March 20, 1987, Newport News; [p.] Joe and Neli Sienko; [pers.] “Find something worth dying for and live for it”
   
9 February 2005, The Arizona Republic (Phoenix, AZ), “Valley rappers tell the world they’re hooked on Phoenix” by Larry Rodgers, pg. E5, col. 2:
With a style that blends the R&B of Beyonce with the soul of Aretha Franklin, Rabouin’s singing lends a soft contrast to the macho approach of Olbert and fellow emcee Deonte Perry on the new CD, Find Something Worth Dying for and Live for It.
       
Google Groups: yhanswers
what happens when a virgin woman is f****ed?
215785
10/6/06
(...)
Find something worth dying for and live for it?
Okay so that wasn’t a question. The question is: What is your greatest passion?
 
8 June 2008, Columbian (Vancouver, WA), “Hundreds Honor Fallen Soldier” by Isolde Raftery, pg. A1:
Hannan recited words a girl wrote in his high school yearbook, many years ago: “Find something worth dying for. Then live for it.”
 
Twitter
Pierre‏
@DeaPierre
i challenege you to find something worth dying for and live for it
3:02 PM - 28 Mar 2009
 
Twitter
Eddie‏
@BluesAndBolts
“Find something worth dying for, then live for it.”
10:31 PM - 19 Apr 2009
 
Twitter
Anonymous 😼‏
@YourAnonCentral
Find Something Worth Dying For
And Then Live For it.
We are the Pulse of #rEvolution! 99% Rising!
#Anonymous
3:38 PM - 16 Jan 2014
 
Reddit—Funny
Find something worth dying for, and live for it. (i.imgur.com)
submitted July 28, 2914 by Jakatut
 
SingularityHub
How to Find Something You Would Die for, and Live for It
By Peter Diamandis - Oct 05, 2015
   
Google Books
The 5 D’s of Destiny
By Olawale Hamzat
Manchester, UK: Kolawole Olawale Hamzat
2016
Pg. ?:
Someone said, ‘find something worth dying for, then live for it.’