Here are a few great quotes by John Owen:
"When sin lets us alone we may let sin alone; but as sin is never less quiet than when it seems to be most quiet, and its waters are for the most part deep when they are still, so ought our contrivances against it to be vigorous at all times and in all places."
“Do you mortify? Do you make it your daily work? Be always at it while you live; cease not a day from this work; be killing sin or it will be killing you.”
"The most tremendous judgment of God in this world is the hardening of the hearts of men.”