Perseverance

Heard on The Dave Ramsey Show:

"Great works are performed not by strength, but by perseverance."
Samuel Johnson

Another one I like:

“Perseverance is the hard work you do after you get tired of doing the hard work you already did.”
Newt Gingrich

And where would we be without Churchill?

“Continuous effort - not strength or intelligence - is the key to unlocking our potential”
Winston Churchill