We’ve started (or tried to start) a congregational conversation about frugality and contentment. In that vein, I have a quote from Albert Einstein. Einstein was not a Christian, but this sentiment of his sure is.
“A calm and humble life will bring more happiness than the pursuit of success and the constant restlessness that comes with it.” 
This quote from a handwritten note that sold at auction for $1.56m which seems to me to indicate that the person who bought it had not yet taken it to heart.
 “Einstein’s Theory of Happiness Sold for $1.5m,” BBC News, October 24, 2017, accessed October 26, 2017, http://bbc.in/2gG8jjr.