Proverbs 4:23 (NKJV) — 23 Keep your heart with all diligence, For out of it spring the issues of life.
Protect the source of life. It is essential to guard the heart diligently, for it determines our life. Often in Scripture, the word heart speaks, as it does here, of our soulish part: the mind, will, and emotions. The words heart and mind are often interchangeable. The importance of a disciplined, well-ordered mind can never be underestimated.
Matthew 15:18–20 (NKJV) — 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.”
Romans 12:2 (NKJV) — 2 And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
2 Corinthians 10:4–5 (NKJV) — 4 For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds, 5 casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ,
1 Peter 1:13 (NKJV) — 13 Therefore gird up the loins of your mind, be sober, and rest your hope fully upon the grace that is to be brought to you at the revelation of Jesus Christ;