Pro 4:23 Guard your heart with all diligence, for from it flow the springs of life.
What does it mean to guard your heart?
In your Bible, ‘heart’ tends to mean the seat of reason or the human will. In our world we’re so influenced by the romantic nature poetry of the 1800s, it’s easy for us to assume that the Biblical authors are speaking about our authentic feelings when they use the word heart. But in general, they mean the will and/or the reason. That being said, what does ‘guard your heart’ mean? The first guide should be the meaning of heart and the meaning of guard. Here are some suggestions just from those word meanings:
- To guard your heart against simple errors in your thinking.
- To guard your heart against simplistic understanding by seeking advice.
- To guard your heart against idolatry by seeking to know the truth about God from his revelation.
- To guard your heart against unsavory influences.
- To guard your heart against evil choices by acknowledging the commands of God and plain moral sense in your decisions.
Another set of hints are in the passage at hand. Here is the ESV translation of the surrounding verses:
Proverbs 4:20-27 ESV My son, be attentive to my words; incline your ear to my sayings. (21) Let them not escape from your sight; keep them within your heart. (22) For they are life to those who find them, and healing to all their flesh. (23) Keep your heart with all vigilance, for from it flow the springs of life. (24) Put away from you crooked speech, and put devious talk far from you. (25) Let your eyes look directly forward, and your gaze be straight before you. (26) Ponder the path of your feet; then all your ways will be sure. (27) Do not swerve to the right or to the left; turn your foot away from evil.
- Listen to and memorize the advice of your elders/parents.
- Don’t engage in evil plans or crooked speech.
- Try to always make progress in character growth.
- Plan carefully.
- Do not deviate from the good, no matter what tempts you.
Two other elements of guarding the heart can be found by looking elsewhere in Scripture. In Genesis 2:15, Adam’s calling is to ‘guard’ Eden. The Hebrew word is different, but the concept is the same. Why was he to guard the garden? Presumably he was to protect it from talking serpents. Similarly, I think that we should guard our own hearts by capturing destructive and evil thought patterns before they can tempt us to sin. Another aspect of guarding the heart could be discerned from Jeremiah 17:9. There, the Lord diagnoses that the heart is deceitful above all else. Because of this, I suggest, we should protect ourselves from our heart. How? Checking our reasoning against Scripture, the advice of others, and the examples of those greater than ourselves. Not only so, but we should guard against the deeply engrained habits of our hearts by diligently seeking them out and replacing them with habits that honor God (Romans 6:12-14).
When I was a new Christian, I swear that every time I heard the phrase, “guard your heart,” it was always in the context of not dating. While telling high school kids to eschew dating was wise advice, it wasn’t quite what the phrase meant. The actual meaning is something closer to a Christian-mindfulness or self-mastery.
How else can we guard our hearts?
 Hans Walter Wolff, Anthropology of the Old Testament (Philadelphia: Fortress Press, 1974), 51. While in your Hebrew Bible, the word translated heart has a wide range of meaning, the core of these meanings is “the seat and function of the reason.” Wolff says that the heart includes, “everything that we ascribe to the head and the brain- power of perception, reason, understanding, insight, consciousness, memory, knowledge, reflection, judgment, sense of direction, discernment.”
 The Greek word in the LXX is the same, though.