Context

This misquoted line is found in 1 Timothy 6:10.

Letter-writing is a lost art, but that's how Paul gets his point across in his three pastoral epistles. (Epistles = letters, hence epistolary novel = novel written through letters. The more you know!)

Back to the point, in the First Epistle to Timothy he writes, "For the love of money is a root of all kinds of evil." Just as letter-writing has fallen by the wayside, so has the correct citation of this quote. Over the years, people have shortened it to simply "Money is the root of all evil." Eventually it will just be emoji form: money bag, tree, devil face.

Where you've heard it

You hear this when someone is criticizing greed and how it ruins everything, like politics and Citizens United.

Additional Notable References:

"Money is the root of evil" sings Monty Python in "The Silly Walks Song."

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

Unless you're living in some sort of free-sharing commune, it's a little pretentious to quote this on your way to or from cashing your latest (evil) paycheck.