Ephesians 6:12

For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.

(v12, NIV)

We humans are made of flesh and blood. God made us that way, and we are frail and fragile. Life comes and goes and we can easily see in the world around us how easy it is for life to be taken from us. However, we struggle not against simply flesh and blood, but far greater things. Here Paul lists the things in which we struggle with and against. We struggle against rulers, authorities, powers of this dark world and the spiritual forces of evil in the heavenly realms. That sounds a lot scarier than simply flesh and blood.

We know that the law is spiritual; but I am unspiritual, sold as a slave to sin. I do not understand what I do. For what I want to do I do not do, but what I hate I do. And if I do what I do not want to do, I agree that the law is good. As it is, it is no longer I myself who do it, but it is sin living in me. I know that nothing good lives in me, that is, in my sinful nature. For I have the desire to do what is good, but I cannot carry it out. For what I do is not the good I want to do; no, the evil I do not want to do—this I keep on doing. Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.

(Romans 7:14-20, NIV)

In Romans 7, Paul talks about this sinful desire that is within us. There is nothing good living in us, but it is our sinful nature. We battle against our own sinful desires which desire us to do things against the nature of God. However, the bible also talks about the way in which we are tempted by the devil. Which is it? Are we dragged along by our sinful nature, or are we tempted by the devil? Maybe they're both one in the same? Or maybe they both work together? Perhaps it's sometimes one and sometimes the other. Regardless, there is a battle to be fought and we are servants of the living God. There are massive forces against us, so we must prepare to face them. To enter without preparation would be like taking the exam of a difficult course in which you are not enrolled in and have not taken before and have no prior knowledge of the subject matter at all. I realize that going unprepared into an exam may be a poor choice for an analogy since there are many "success" stories about this. However, most of those stories I believe the person had at least some preparation, regardless of whether they'll admit to it or not. There may have been courses they attended throughout the term, or homework they did prior. Maybe they already took the course or had past knowledge of the subject matter. Maybe they did in fact cram a few hours before the exam. However, this battle in which we are facing is against such opposition that is greater than any difficult exam you have ever taken or could ever take. Therefore, prepare yourself. We draw from his strength, and it is through his strength in us that prepares us for these trials. We cannot succeed apart from him.