Lets first examine the verse in question:
"Since we have these promises (2 Cor. 6:18), dear friends, let us purify ourselves from everything that contaminates body and spirit, perfecting holiness out of reverence to God.
-2 Corinthians 7:1 emphasis mine-
A surface reading of this seems to imply health and wellness by a process of removing those things which contaminate us. You may be thinking, "I have already done this, and I am still miserable." Let me encourage you to delve deeper.
What sorts of things contaminate the body?
Seems like a simple question to answer. You may be thinking that excess smog, eating too much sugar, consuming drugs and alcohol may warrant the tag of bad for your bodily health. While this is certainly true, are their other things that constitute a pollutant for the body?
I want to suggest there certainly are but only when we consider these in light of the second part of Paul's command, the spirit.
In the relationship between the mind and the body we can observe some simple things. When we take a medication for back pain we are also alerted to the potential side effects of the drug. Among these are a list of physical symptoms such as dry mouth, itchy throat, or perhaps stomach discomfort. Yet there are another category of symptoms quite their own. You may feel confused, have hallucinations or acquire a general feeling of malaise. Some of the symptoms of medication are so extreme as to cause suicidal ideology and actions. Though these symptoms can be brought about by a physical substance, namely a medication, the results can cause symptoms of the mind to occur altering the mind state. Notice I did not infer some brain-chemical change, however this may be involved. Rather I am referring to what happens to a person's inner man, his spirit, when he ingests something not prescribed for his consumption.
This last sentence was not intended to make you think any longer about ingesting medication as it was more aimed at your willful imbibing of physical stimuli. When we listen to music some are said to experience any range of emotions from euphoria, passionate frenzy, a sense of tranquility, anger, skepticism towards life and violent brooding. How can a physical stimuli like sound waves produce a mind state that causes these range of emotions?
It seems Paul was on to something more than just sour milk and a lack of exercise. Paul was referring to the unique relationship between mind (spirit) and body. No doubt we have all watched a movie and then become inspired by the tale heroism and self-sacrificial service that it motivated us to do something for someone else. But what caused this physical reaction? The very delicate relationship between mind and body can be the explanation.
What can we do about it?
If what we ingest, either physically, visually or audibly causes a change in our mood, should we not be more aware of what kinds of things we are subjecting to our consumption? I say we should be.
I have recently been removing any television programming that contains messages that cause me to speak abruptly to my wife, treat women as objects of lust and show gratuitous sexual situations. Though this is only one part the result of this action will reverberate into the other areas of my life. By removing these sense stimuli my spirit is refreshed, uplifted and encouraged to carry on the fight against the tendency to relent to temptations of all sorts.
This sort of effect can be the same for you. If you are down, listen to uplifting music or watch a funny movie, if you need encouragement open up your Scripture and read or talk with a good friend who will pray with you. Also remember that bodily exercise can help the spirit by increasing the flow of endorphins in your body which will uplift your mood.
Lastly, choosing the right foods also can have a positive effect on your spirit. First it will allow your body to properly process the energy and remove the wastes. Have you ever felt anxious after you ate a big meal or how about the way you feel mentally when you have food poisoning? The opposite is also true, intake the right fuel and your mind will thank you. Second, your brain will be stimulated with the right fuel to ensure your stress levels stay low and your joy is more complete. Lastly, by exercising more frequently you can enchance your self esteem by viewing your body in a more positive light. Many of us have desired to feel better about our bodies and some have a low sense of bodily image. With proper nutrition and exercise you will feel better overall about who you are.
With this new sense of mind and body health you can more completely serve the kingdom of God. This perfecting of holiness then can be seen as a worshipful act towards our heavenly creator who has created our bodies to function at their best. Yes we will still suffer setbacks, emotional and physical trials but by watching our intake of all sorts of stimuli that has a negative impact on us we will be more equiped to handle the trials when they come.
I hope this was encouraging to you. May you find God's best health for you this day!