You would never leave anything that is valuable or important to you such as jewelry, money, or fine art work out in the open; exposed so that anyone could have access to them. You put them in a place that is safe and guarded, so that nothing can damage them and they can't be stolen. In fact, the greater the value, the more protected you make these objects and the less access you give to anyone who might have the desire or capability to harm or steal them.
Perhaps then, this is why Proverbs 4:23 says, "Guard you heart with all diligence, for out of it flows the issues of life.
Your heart is your most precious possession - not just your physical heart - but your spiritual heart.
Your physical heart is protected from harm by the sternum, ribs and spine; bones that make it difficult for anything to have access to it or damage it. That is because your heart is so vital that you can not live without it. You can live without arms, legs, eyes, ears, a kidney, spleen, appendix, or portions of your liver or intestines or even parts of your brain - but you can not live without your heart.
If your heart is damaged by disease or injury, you are severely limited in what you can do. You can't get the life-giving oxygen that your body needs in order to be healthy and your capacity to live normally is diminished. If it is not healthy - you are not healthy.
In the same way, we must protect our spiritual heart from any thing that would harm it or diminish it's capacity to let the life of God that dwells in it to flow to us. His life flows to us from His Spirit that dwells in us - in our hearts; so we must have an alive, free and healthy spiritual heart to live - to really live in the way we were created to live.
But your heart is the object of a fierce battle. Remember, that you have an enemy who is both skilled and intent on your destruction. If He can't kill your heart, he wants to keep you in bondage and restrict your freedom to live from your heart.
- Without a healthy heart you cannot love - either God or others.
- Without a healthy heart you cannot have faith.
- Without a healthy heart you cannot fulfill your desires, and ultimately your destiny.
- Without a healthy heart you cannot really live.
So, we must fight for our heart - to keep it free and healthy.
But this is a battle that we can win because Jesus, our Warrior-Savior has defeated our enemy and has given us authority to enforce his defeat.