Matthew 15:11, 18-20 New King James Version (NKJV)
11 Not what goes into the mouth defiles a man; but what comes out of the mouth, this defiles a man.”
18 But those things which proceed out of the mouth come from the heart, and they defile a man. 19 For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies. 20 These are the things which defile a man, but to eat with unwashed hands does not defile a man.”
Why do we need a heart that is not defiled?
To enable us to host the Holy Spirit, our Guide, our Comforter, our Helper. With the Holy Spirit, we are guided to build a great life (a life abundant) that Jesus had promised to fulfill. With the Holy Spirit, we are enabled to conquer fear, we are enabled to love, and we are enabled to have self discipline.