Ephesians 6:10-20 10 Finally, be strong in the Lord and in the strength of his power. 11Put on the whole armour of God, so that you may be able to stand against the wiles of the devil. 12For our struggle is not against enemies of blood and flesh, but against the rulers, against the authorities, against the cosmic powers of this present darkness, against the spiritual forces of evil in the heavenly places. 13Therefore take up the whole armour of God, so that you may be able to withstand on that evil day, and having done everything, to stand firm. 14Stand therefore, and fasten the belt of truth around your waist, and put on the breastplate of righteousness. 15As shoes for your feet put on whatever will make you ready to proclaim the gospel of peace. 16With all of these, take the shield of faith, with which you will be able to quench all the flaming arrows of the evil one. 17Take the helmet of salvation, and the sword of the Spirit, which is the word of God.18 Pray in the Spirit at all times in every prayer and supplication. To that end keep alert and always persevere in supplication for all the saints. 19Pray also for me, so that when I speak, a message may be given to me to make known with boldness the mystery of the gospel, 20for which I am an ambassador in chains. Pray that I may declare it boldly, as I must speak.
Read the whole passage and let it seep into your mind for a minute.
I know you've seen this passage transformed into a colorful, almost comical meme at least once. A lot of people seem to use it as a sermon outline. They start with forces of wickedness and powers not of this world and end up with a sermon about the dangers of premarital sex. Sexual morality is important but sexy feelings are not what Paul was worried about.
Roman Empire? Part of it, sure, but I think he was convinced that there was something else behind his current trials. Something darker and more primal than even a Roman emperor. (That's saying something, look those guys up sometime.) Darkness like that feeling something is going to crawl out of the shadows and hurt you in ways you can't even imagine. The thing that crawls out from under a rock to make people do terrible, dark things. The shadow you feel on someone, and find out later that they raped a child or killed someone. The kind of stuff you feel like a fool for believing in the daylight hours and try to shrug off at night.
The thing is, it's real. It's real and it's scary as hell (because that's where it's from!) and what is going to save you when that happens is that whole armor of God. The thing that is going to come to your aid in that hour is the thing you put into your mind every single day. What are you going to say to the creeping thing under your bed? If your heart and your mind are soaked in scripture and prayer, the words are going to come. They're going to come out of your mouth like breathing. You're going to trust your instincts and not date that man who seems so nice but makes your skin crawl. When Satan comes knocking on your door, offering you power and badly desired outcomes, you will know to say turn him down because you already know how the story ends and that God will take care of you.
I'm not suggesting everyone make sure they have Rite II memorized and take up demonology as a hobby. It's very dangerous. (Hence the exorcist needing an exorcism in the movie ) But if you find yourself faced with evil, real primal dirty evil, God is going to take care of you if you use the tools at your disposal.
Just don't forget to keep them clean and ready.