Rule #18 Guard your heart.

I mentioned several days ago that I'm getting better at my workout. I didn't mention my response. I added a 2min job to my 30min workout. At the 5min mark (allowing for a solid warm-up) I do a 2min job then drop right back down to my usual pace. I read a book on running. It was specifically trying to make running fun. In the past I've always tried to maximize growth by doing cycle training. 2min run, 2min walk, 2min run. It sucks. But this book suggested instead to simply start by walking every day. Then when that becomes easy, or at least routine, add a 2min run. When that is routine change it to 4min, then 6min, etc. Until the entire set is a continuous run. So that's what I'm trying. My total workout being 30min, and wanting to have a decent warm-up, cool-down time. I would like to have a 5min walk, 20min run, 5min walk workout. To increase from there I simply increase the pace of the run. After adding the 2min run I didn't hate myself like I usually do is cycle training. I just enjoyed the fact that I got a brief run in there. It makes running a little more fun and follows my goal of sustainability. I'm not going to set any timeframe for when I will increase the running time. That would be self-defeating. Instead I'll just take it as it comes. When I am disappointed the 2min run is over I'll make it 4min. This will also allow me to get closer to my 10K steps per day goal. As going faster will mean more steps during my 30min workout.
For the sake of this post and this rule the heart is "The seat of passion", a conglomeration of the mind, the will, the emotions, the soul, the social piece of who you are.
Rule #18 may seem a duplicate of Rule #17 but it's really more of a complement. Peace is the first perimeter guard to your heart. When your peace is violated what is in your heart comes pouring out. And that is why it is important to guard your heart as well. Your peace will be violated and what is in your heart in that moment will determine how many people you hurt that day. 
Your heart carries inside it all the things you feed it. The old adage "you are what you eat" is a nice way of thinking about it. The adage is only partially true from a bio-chemical standpoint. If you eat a pig you are not a pig. Inside your body chemical processes breakdown the meat to different pieces most notably: protein, carbohydrate, and fat. While you are not a pig these three component can only be extracted if they are present. Eating a piece of candy will not make you a piece of candy but it will make you weak as it is nothing more than simple carbohydrates. Without protein the body cannot build or maintain muscle. In the same way if you eat nothing but protein you will have no energy. Muscles need carbohydrates for energy to allow the muscles to contract. If you have no fat you will constantly be sick, unable to maintain your body temperature, and probably sluggish in your thinking as fat is food for the brain and nervous system. None of these items can be developed without consuming them.
The heart has a similar set of requirements. Let's call them passion, fun, and rest. 
Passion is what you wake up for in the morning. A purpose bigger than yourself. A purpose you were born to serve. Everyone has them and without them we are weak and useless. My passion is Jesus, creative problem solving, teaching, and philosophy. If any of these were taken from me I would wither and die and the process wouldn't bother me a bit. Passion provides you with strength and effectiveness.
Fun is the carbohydrate of the soul. It gives you energy. So often people say "The joy of the Lord is your strength." But these people have no idea what the "joy of the Lord is." I was in a class where the joy of the Lord was defined as supernatural uncontrollable laughter. Maybe that is one form of it but it's not the most common one. No the most common form of the joy of the Lord is simple fun. Read the rest of Nehemiah 8:10 and see. A key part "eat the fat and drink the sweat". You could paraphrase this eat a rib-eye steak and a coke (or some spiced wine). It's not talking about some abstract idea of supernatural joy manifesting from spirit to soul. It's actually going the opposite. This joy goes from flesh to soul to spirit. The flesh is part of being a human, God created it, and despite the effect of the fall on it, the flesh is a power piece of you. Fun is the ingredient that gives you energy and is the substance needed in greatest abundance. I personally recommend you find a job you enjoy for this very reason.
The final piece is rest. I still remember my old missions directors wise words: "sometimes the most spiritual thing you can do is sleep." Missionaries are passionate, devoted, self-sacrificial people. And without this simple advice they would all be burned out in a couple days. Sleep is necessary. Like fat rest is probably the least necessary of the elements but without at least a small portion of it the body will stop functioning. The brain will grow sluggish. The body will stop doing what it's told. And after a meager 3 days hallucinations, and after 10days death. God rested the 7th day and commanded us to do the same. It's because he built us, our hearts, to feed on rest.
Guarding your heart (soul, mind, will, emotions) means feeding it what it needs as it needs it. Take away any of these substances and you'll get depression, fatigue, irritable, and be ineffectual. Take any one to much and you will get fat, temperamental, arrogant, and be ineffectual. Pick a passion, enjoy pursuing it, and take the time to rest so you can do it every day.


Extending the metaphor beyond reason could add a few more ingredients. The less fun things your heart requires such as personal growth, challange, etc could be considered the vitemens of the heart.

And well beyond a resonable metaphor now is water. It's 80% of your body and needs to be refreshed daily. That's your time with Jesus.