"This is sin; a refusal to listen to the voice and to the Word of God. So that if you are living your own life in a very respectable manner, and are not listening to God, you are still a terrible sinner. If you are living that little self-contained, self-satisfied life in which you really only think of God now and again, and remember perhaps morning and evenings that there is a God, and you say your prayers; if that is your attitude to God, if you are not waiting upon Him and listening for His Word, and seeking it everywhere, and living to practice it, then you are as much a sinner as the drunkard or adulterer; you are not listening to God. That is the essence of sin."
- D. Martin Lloyd Jones