Ephesians 6:10-18 plainly describes that war, though other verses discuss it, too. We won’t go verse by verse through it, but here are some main points.
The most important verse here is Ephesians 6:12. There are good and bad angels. They don’t look like the cartoon versions we think of. But, in one small way they are, as the bad ones can try to tempt you to do something wrong, and the good ones try to encourage and strengthen you, as they did Jesus after he was tempted by the devil. (Matt. 4:11) They also do other things, unseen in the physical realm.
If you’ve trusted Jesus Christ as your Savior, though, you have God living inside you. So, you can overcome that, as long as you don’t quench the Spirit. However, it’s important to remember a couple things.
First, we must be strong in the power of His might. (Eph. 6:10) We can’t win battles on our own. It would be like one person playing football against an entire team. Angels are very powerful. They inspire enough awe that they cause even saints to bow down to them, although they refuse worship. (The “Angel of the Lord” that some bowed to in the Old Testament was Jesus Himself, in spirit form. So, He did not refuse worship, because He is the Lord.)
Second, the devil is sneaky – that’s why his wiles are mentioned. Yes, he walks about “like a roaring lion, seeking whom he may devour.” (1 Peter 5:8) But, he does it in a clever way. He doesn’t go up and boldly throw evil in someone’s face most of the time. He goes after the weakest link, like a lion chasing prey.
So, for instance, take King David’s weakest point. The devil didn’t just have Bathsheba show up at his door. Instead, when David couldn’t sleep, he went up on his roof. When he saw her, the devil planted just a little thought of, “Isn’t she nice” in his mind. That seed was allowed to grow, and it grew into more and more sin.
