12 For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 13 Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm.
The chief reason we need to put on the whole armor of God is because of who our enemy is. The Bible tells us that we do not wrestle against flesh and blood. No matter what it looks like in the physical world, our real foe is not a flesh and blood enemy. We may have battles and forces that appear to be physical. There may be fights and arguments that take place between people and political structures for very moral and upright reasons. But underneath are the spiritual forces that are at work.
Our actual wrestling is with principalities, powers, and the rulers of the darkness of this age. Paul uses the word “wrestle” because it demonstrates how close the conflict is to us. Wrestlers are in face-to-face, body-to-body competition. It’s not like lobbing a missile at an enemy a thousand miles away. Spiritual wrestling is in-your-face wrestling!
The enemy is described as being principalities, powers, rulers of darkness, and spiritual enemies in heavenly places. Our enemies are the spiritual forces that are at war with God in the unseen realms here on earth as well as in the heavenly places.
Satan, of course, is the chief of these hordes. He hates God and he is out to do anything he can to defeat God and the people of God. He knows our characteristics. He knows the flaws that sin has introduced into the human race, and he knows how to capitalize on those weaknesses. This is a tough enemy we are up against, but not an insurmountable one if we make use of God’s armor and methods.
“Therefore,” Paul says, “take up the whole armor of God.” Why? so that we might be able to withstand the onslaught. And in the end, having done all, we are to still be standing. The phrase, “having done all” is an important one. The battle is not won by doing nothing. We are to give our all to the conflict. Having done all; having put on the whole armor; having fought the good fight; having resisted, where that is called for. Having done all, to still be standing when it’s over. That’s the goal.