“To fear is to die every minute.”

Variant: Every breath is a choice. Every minute is a choice. To be or not to be. Every time you don't throw yourself down the stairs, that's a choice. Every time you don't crash your car, you re-enlist.
Source: Survivor

Source: The Sand Pebbles (1962), Ch. 19; marriage ceremony of Maily and Frenchy
Context: He had a light in his gaunt face and his voice and manner were strangely solemn. The were all a bit afraid of him. … "We're mixing our lives together, Maily, and we'll never be able to unmix them again, and we'll never want to." His voice was strong but tender, and he was smiling down at here. "I take you for what you are, and all that you are, and mix you with all of me, and I don't hold back nothing. Nothing! When you're cold, and hungry, and afraid, so am I. When you're happy, so am I. I'm going to stay with you all that I can, take the very best care of you that I can, and love you every minute until I die." He took a deep, slow breath. "Now you say it"
"I will always love you and honor you and serve you, Frenchy, and stay as near to you as I can, and do everything for you, and live for you, and I won't have any life except our life together…" Tears welled out of her eyes but she smiled steadily up without blinking. "I will just love you, Frenchy, all of me there is just loving you forever."

Animal Dreams.
Animal Dreams (1990)

Source: The Passage Trilogy, The Passage (2010)

Commonly attributed to Barnum, there is much testimony of contemporaries that he never actually said this, and in "P. T. Barnum Never Did Say "There's a Sucker Born Every Minute" http://www.historybuff.com/library/refbarnum.html R. J. Brown asserts that it actually originated with a banker named David Hannum, in reference to one of Barnum's hoaxes: a replica of the Cardiff Giant.
Misattributed

Source: The Lucky One

Hugo to Jessica, on his plans to kill Hoederer, Act 5, sc. 2
Dirty Hands (1948)

Source: Requiem for a Dream

"Belief & Technique For Modern Prose: List of Essentials" in a letter to Arabelle Porter (28 May 1955); published in Jack Kerouac: Selected Letters 1940-1956 (1995). Sometimes misquoted as "Be in love with your life every minute of it."
Variant: Be in love with your life every detail of it