The world is yet to discover the knowledge of the human spirit, they know everything about the body and its functions, they know everything about the power of the mind and positive thinking. There are many books about the power of the mind and positive thinking, these are good books, I've studied many of them. And the are many books on how to build muscles of the body and keep it in health, also good books. The human spirit is the most important part of the human being, he is the one who controls what happens in your life. Everything in your life is the outflow of what has already happened in your spirit man. So if there is a problem in your environment don't look to solve it physically, deal with the root cause of it in your spirit. The body and his senses are responsible for collecting information, whatever you see,touch,hear,feel,taste is information, which is then sent to the mind for processing and when the mind is done, the information is deposited into the human spirit and the human spirit produces or manifest in your environment, the fruits according to the seeds sown. Information is seed, your mind processes the seed and your spirit is the ground where the seed is sown. Your mind is the doorway to your spirit, so be careful what information you allow. If you sow thoughts of death, failure, sickness, in the ground of your heart that's what you will reap in your environment. Proverbs 4:23 Guard your heart with all diligence for out of it are the issues of life. Choose to allow in your mind only what is good, uplifting, encouraging, hopeful, lovely, true, and you will produce fruits after these seeds. Stay away from negativity, surround yourself with an atmosphere of faith. Philippians 4:8 Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.