John Green said this quote

Cover me!' Augustus said as he jumped out from behind the wall and raced toward the school. Isaac fumbled for his controller and thenstarted firing while the bullets rained down on Augustus, who was shot once and then twice but still ran, Augustus shouting,'YOU CAN’T KILL MAX MAYHEM!' and with a final flurry of button combinations, he dove onto the grenade, which detonated beneath him. His dismembered body exploded like a geyser and the screen went red. A throaty voice said, 'MISSION FAILURE,' but Augustus seemed to think otherwise as he smiled at his remnants on the screen. He reached into his pocket, pulled out a cigarette, and shoved it between his teeth.'Saved the kids' he said.'Temporarily' I pointed out.'All salvation is temporary' Augustus shot back. 'I bought them a minute. Maybe that’s the minute that buys them an hour, which is the hour that buys them a year. No one’s gonna buy them forever, Hazel Grace, but my life bought them a minute. And that’s not nothing.