How many desires do you have which you kind of wish you could squelch pretty quickly so you didn't have to deal with them? If you are like the average person, probably a few a day or more! It might be the desire to reach out and slap that person who is acting pretty stupid right about now, or the desire to indulge your sweet tooth with the biggest and gooiest of treats in the dessert counter. Some of the desires are because of something totally internal while others are kind of dependent upon another person or someone else's actions, right? It doesn't really matter where that desire "comes from" as long as we learn to sort out the ones which are correct to act upon and turn away from the ones which aren't.
People who are ruled by their desires think only of themselves. Everyone who is ruled by the Holy Spirit thinks about spiritual things. If our minds are ruled by our desires, we will die. But if our minds are ruled by the Spirit, we will have life and peace. Our desires fight against God, because they do not and cannot obey God’s laws. If we follow our desires, we cannot please God. You are no longer ruled by your desires, but by God’s Spirit, who lives in you. (Romans 8:5-9 CEV)
This idea of being "ruled" by our desires can be a little overwhelming, though. To recognize we are "ruled" by anything is kind of frightening, because it means we are a little out of control and we all know how much we all like to be in control! I have to ask though - how's that "you being in control" been working out for you? If you are like me, then you'd probably acknowledge it isn't working very well because we aren't all that reliable and trustworthy to be the "controlling agents" of our lives.
As Paul indicates, there are really two sources of "control" in our lives - either our own desires, or the action and control of the Holy Spirit in our lives. One is less than reliable, the other is infinitely reliable and totally trustworthy. "Rule" or "control" has one central location in our bodies - it is our mind. Whatever has control over our minds is what determines our actions. This is why many spiritual leaders have written so many books about the "battle of the mind" - because it is a battle of control!
Look again at our passage. Our desires do not and "cannot" obey God's laws - they are in opposition - they act as resistance in our lives. The whole idea of having a parking brake on a car is to give just a little more "resistance" to the wheels while parked on any kind of an incline so that there isn't any "slippage" which would allow the vehicle to start moving in the direction of the bottom of the hill. Think of the Holy Spirit as that agent in our lives who helps us avoid "slippage" into places and actions we should not be in!
If this idea of the battle being in our minds is really the issue we need to consider, then let me just be the first to acknowledge the mess my mind is in! I have so many thoughts running through that "space" every day that it sometimes is quite overwhelming. The sheer volume of what we "take in" and have to "process" in our thoughts each day would probably confound some of the most advance computers of our day. Yet, our minds keep up with all of it, often without us even consciously having to address those thoughts - we just respond.
Herein is the rub - what we respond to without conscious thought may be our undoing! This is why it is so essential our desires be controlled by someone other than us. We might not recognize the danger in the action we are about to take, but the Holy Spirit will. We need a "filter" over our desires so that we respond with consistent obedience in our lives. We won't hit the mark each and every time because we sometimes just let stuff get past our conscious thought and the niggling of the Holy Spirit gets ignored. Yet, we have been given his "rulership" over our lives - helping us sort out these desires - so we can learn obedience.
Did you catch that? Obedience is learned. It isn't "soaked in" through osmosis, nor is it something delivered to us on a silver platter. Obedience is learned - through wrong responses, right choices, and even avoided mistakes. Desires aren't changed overnight - so obedience isn't an overnight thing either. What we need to understand and accept is that obedience is a daily choice - allowing more and more of our desires to be ruled over by the one who is most reliable - the Holy Spirit. Just sayin!