"A Charlie Brown Christmas" wasn't intentionally created to be timeless, but because of its simplicity and sincerity, timeless it is. Miraculously, it avoids every cliche associated with children's animation and is a perfect blending of music, words and images that clearly conveys one man's vision and philosophy -- Charles Schulz, who drew "Peanuts" from 1950 until his death in 2000.
Schulz and Peanuts: A Biography, by David Michaelis
A Charlie Brown Religion: Exploring the Spiritual Life and Work of Charles Schulz, by Stephen J. Lind
"How 'A Charlie Brown Christmas' Almost Wasn't," Jennings Brown, ny.com, November 16, 2016
"The 'Charlie Brown Christmas' Special Was the Flop That Wasn't," Carrie Hagen, smithsonian.com, December 9, 2015