Keep thy heart with all diligence; for out of it are the issues of life.
Your heart determines your life. This is one of the most important proverbs. Blessing or grief in your life depends on ruling and training your heart. If you direct and instruct your heart with godly inputs, there is no limit to your potential success before God and men.
Every sin starts in your heart, and your character and speech reflect your heart. You can only pretend to be different than your heart for a short time, for it will quickly regain control and dictate your actions. Others know your heart by your words and choices.
David was a man after God’s own heart (Acts 13:22). What a description! This should be your life goal. How? David guarded his heart by careful self-examination, confession, prayer, friends, singing, etc. (Ps 4:4; 9:1; 15:2; 17:3; 19:8,12,14; 24:4; 26:2; 27:3,8,14; 28:7; 32:11; 34;18; 37:31; 51:10,17; 57:7; 61:2; 62:8,10; 66:18; 77:6; 84:2; 86:11-12; 101:2-5; 108:1; 111:1; 112:7-8; 119:11,32,36,63,111; 139:23-24; 131:1; 141:4-5).
Your heart is your greatest asset, for it can do more for you than anything else. It is much more than the muscle beating 70 times a minute in your chest. You need to consider and prize the inner, decision-making part of you that loves certain things and chooses to do them over other things. Learn to set your affections on good things (Col 3:2; Matt 6:21).
You can keep your heart good, or you can let it become bad. You can be diligent in this project, or you can be lazy. God’s children have an old man that tempts them to evil, but their new man calls them to godliness. Your heart must decide between the two often. Every person makes a series of choices each day. What are you going to do today?
Whatever is in your heart comes out in your life. If your heart is full of good things, your life will show that goodness; if your heart is full of sinful thoughts, your life will show them. The large tests and decisions you will face many times in life are dependent on your heart, and so are the small choices that you make hundreds of times a day.
Is your heart pure? Are you working to keep it pure today? Do you know that laziness in this matter will bring severe trouble and pain to your life? You must eliminate negative inputs to your heart e.g. Hollywood entertainment, foolish or sinful friends, and worldly music. You should feed your heart with the Bible, prayer, godly music, and holy friends.
Jesus Christ condemned the Pharisees for emphasizing man’s outward appearance; He emphasized man’s heart instead. He said the following in two different places: O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things.
Matthew 12:34-35 But those things which proceed out of the mouth come forth from the heart; and they defile the man. For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: These are the things which defile a man: but to eat with unwashen hands defileth not a man.
Matthew 15:18-19 Sin begins in the heart. Lust for a sin attracts your heart, so you think about it. If you think about it enough, you will do it. The result of this choice is death. Protect yourself by keeping your heart diligently from sinful thoughts (James 1:13-16). God sent the Flood to drown the earth for their wicked imagination (Gen 6:5), so hate any evil fantasies.
Think about an evil heart and how it affects the various issues of life. Sexual fantasizing will lead to filthiness, fornication, adultery, or defrauding your spouse – all because you allowed sinful thoughts in your heart. The same is true of bitterness toward others, coveting things you do not have, pride, excess ambition, envy, and other sins like them.
If you do not think about sin, you will not commit presumptuous sins. If you do not mull over the possibilities, you will stay away from those temptations that can destroy you. This rule works in all sinful lusts and actions, whether sexual fantasies or resentment of another person. The less you consider sinful words or actions in your heart, the more you will build up inhibitions against those sins. Ruling your heart will dictate your conduct.
If you think about God and godliness, with an affectionate and eager desire to please Him, your life will show more and more righteousness in your speech and actions. If you only think kind and loving things about another person, you will treat them that way. This is the opposite of allowing bitterness or resentment to build up in your heart. If you set your love on God, His worship, and His people, your conduct will be better and better.
How can you keep a pure heart? Protect it from influences toward sin (Ps 101:3; I Cor 15:33), and supply it with influences toward holiness (Ps 119:11,63; 101:6). Get away from evil things, and spend your time with good thoughts and things (Phil 4:8). This is actually quite simple, but it takes strong personal commitment and discipline to do it.
Since even thinking about foolishness is sin (Pr 24:9), and desiring another woman is adultery in your heart (Matt 5:28), you must often examine your heart with the Lord’s help (Ps 139:23-24). Hiding scripture in your heart by reading, meditation, and memorization will further protect you from sinful thoughts (Ps 119:9,11,15,105).
Jesus Christ sees your heart clearly and fully (Heb 4:12-13), so He will reward diligence if He sees a faithful heart (II Chron 16:9), and He will punish folly if He sees a heart with idols set up in it (Ezek 14:3-8). It is foolish to think He does not see every idea and thought of your heart (Jer 17:9-10; Rev 2:23). He knows you better than you know you.
As David kept his heart, you can keep and perfect your heart. Remember, he was careful and faithful to examine himself, to confess his sins, to pray, to delight in God’s words, to choose only godly friends, to give thanks and sing praises to God. These heart exercises will keep your heart noble and righteous, and keeping it like this will bring God’s favor.
Solomon taught you to work at fearing God each day. He wrote elsewhere, “Let not thine heart envy sinners: but be thou in the fear of the LORD all the day long” (Pr 23:17). The apostle Jude put it this way: “Keep yourselves in the love of God” (Jude 1:21). You can and will stop loving and fearing God, if you allow sin to harden your heart (Heb 3:12-13). Never forget this proverb, and with God’s help and strength, keep your heart diligently.