Do you know that the devil is fully aware of your weaknesses? He knows your particular blind spots, your vulnerabilities. He knows which sins you struggle with the most. He knows what things irritate you, frustrate you, and distract you. He knows exactly what desire or longing is specific to your personality and wiring. And he is every day working the angles to exploit them and bring you down. Satan has a file on you, and he is working it every minute of every day to make sure you fall.

Do you ever think about it that way? The enemy is often more conscious of our weaknesses than we are. And he will do whatever it takes to get us to neglect our faith and forget the grace of God. If he can get us to stumble or use us to get others to stumble, he will not let up until he’s done it. All because he hates Jesus and wants to see Jesus’ glory obscured or diminished in the world.

It is for this reason that Paul’s words are so strong on the subject of the spiritual war. This is not something we can afford to be nonchalant about. The apostle Peter warns us: “Be sober-minded, be alert. Your adversary the devil is prowling around like a roaring lion, looking for anyone he can devour” (1 Pet. 5:8). This is how Paul informs our preparation:

Finally, be strengthened by the Lord and by His vast strength. Put on the full armor of God so that you can stand against the tactics of the Devil. For our battle is not against flesh and blood, but against the rulers, against the authorities, against the world powers of this darkness, against the spiritual forces of evil in the heavens. (Ephesians 6:10-12)

The first rule of warfare is practical awareness of the enemy. You can’t fight well if 1) you don’t know who you’re fighting, and 2) you don’t know where they are. Knowing your enemy’s character (what they’re willing to do) and their position (where they may be attacking you from) is a key component to successful warfare. Paul is telling us two things here that are of utmost importance. He’s telling us that our enemy is the Devil, not our fellow man. This is important because we often mistake the unbelieving world as our battle targets. But Paul says we don’t war against “flesh and blood.” Because sin is in all of us, even those justified by the blood of Christ cannot justly carry out the fight against other sinners. The ground is level at the foot of the cross. Unbelievers, by definition, are unenlightened to the things of the Spirit. They are not the enemy.

But we also need to remember the enemy’s position. He attacks us from the spiritual realm. Very often, Christians try fighting the devil’s wiles in the devil’s ways. We assume legalistic behavior will solve our sin problems, for instance. But the devil is totally fine with all of us becoming more religious, so long as we don’t actually love Jesus. No, we cannot wage a spiritual war with human strength. We have to be “strengthened by the Lord,” operating under “His vast strength.” We can’t do it in our own power.

When the enemy attacks our hearts, we don’t want our self-righteousness standing guard, but the breastplate of actual righteousness, Christ’s righteousness. When the enemy whispers his accusations into our ears with his forked tongue, we don’t want some trite, social media-quality daily affirmations sitting there; those would protect us about as much as cotton-ball earmuffs. But the helmet of salvation is another story. If my mind is ready with the great salvation of the gospel encasing it like a force-field of grace, I am really prepared.

Which is why we must wear this armor constantly. We should never take it off. We should wear it to bed as pajamas. We should make sure we’ve got it on first thing in the morning by turning to the gospel as immediately as possible. This is wartime. Don’t take the armor off. You don’t try putting on your seatbelt when you see the Mack truck bearing down on you at 60 mph; you put it on before you pull out of the garage. Likewise, don’t wait for the enemy to show himself before you start suiting up. You don’t know when the attacks will come; best to sleep with your boots on and your sword by your hand.