Do not give the devil an opportunity.
When it comes to sin, the devil shows up.
He showed up in the garden of Eden before the fall of man (Genesis 3, Revelation 12:9). He sprung his web of temptation, a web of deception, and caught humanity. Through it, he landed the franchise of the human soul.
Paul said it this way: through one man - Adam - sin entered into the world (Romans 5:12). Adam gave the devil an opportunity. He gave the devil a door to walk through, gave the devil an opportunity.
And through Christ, God landed His own franchise of souls. Paul said it this way: through another man – Christ – many will be made righteous (Romans 5:19). Christ was the door for us to walk through to God.
When God told Satan that Job was a good person, the devil wanted to have the last laugh. He was thrown into difficulty, but he came out unscathed. He did not give the devil an opportunity, a door to walk through.
When the Father vouched for the Son with a voice from heaven (Matthew 3:16–17), the devil wanted the last laugh with the temptation in the wilderness (Matthew 4:1–11). But He overcame. He did not give the devil an opportunity, a door to walk through.
With this verse, Paul is treating unaddressed sin as giving the devil an opportunity.
And those who say the devil cannot be in two places at the same time should rethink. Those who say that envision Him as if He were a man; they envision Him with human limitations.
They imagine Him as if, if He is in one place doing something, he cannot at the same time be in another place doing another thing. They are overthinking it, in my opinion.
They are starting from who man is and projecting who the devil is from that. They are mistaken.
They try to present a vision of the devil's limitations, saying He does not know all things, is not everywhere, and is not all-powerful, almost suggesting you can insult Him.
They try to make sure we do not give Him too much regard. But the Bible encourages neither a dismissal, downplaying of the devil nor a preoccupation with the devil.
It is enough that the devil wants us to sin and He tempts in that direction. And it is a lifelong struggle not to sin, hence the need to put on the whole armor of God (Ephesians 6:10-18).
What advantage do I get from the fact that the devil does not know everything? He knows enough to be a menace and to be an extremely effective tempter, for sure.
What advantage do I get from knowing that the devil is not everywhere? The imagination is that there are 8 billion people on earth, and if the devil were going to and fro, he could probably get to one person once every 10 years?
Does the devil need to book a plane ticket and check in at airports, too?
Of what advantage is it for me to know that the devil is not everywhere at the same time? My conclusion is that, as a spirit, the speed with which he moves (if we can use that word), he could as well be everywhere at the same time, for all I care.
Paul's saying, "Do not give the devil an opportunity," is not an invitation to meditate on the devil and how he is limited in this way or that. He is near enough to do severe damage by taking advantage of weaknesses to trap me in sin and disobedience.
Peter warned that our adversary, the devil, like a roaring lion, is on the prowl looking for someone to devour (1 Peter 5:8). That is why Paul says, “Do not give the devil an opportunity.”
No one is inviting you into an exploration of Satan and who he is; Jesus said, Don’t bother about those who want to dig into the deep things of Satan (Revelation 2:24).
And when the devil says he moved to and fro the earth in Job (Job 1:7; 2:2), don't think the devil is as constrained by time, space and gravity as we are. In short, don't overthink. Of what profit is it?
Paul said, "Don't give Satan an opportunity." That means the devil will use what you give him. It is a call for high sensitivity.
Do not give the devil an opportunity means don't create an environment where the devil's operation can flourish, not in our minds, not in our lives.
And that environment is where you are not aware of sin, and are therefore not having a negative emotional reaction to it, as the previous verse says: Be angry and do not sin; do not let the sun set on the cause of your anger.
But if you have bitter jealousy and selfishness in your hearts, do not boast and tell lies against the truth. Such wisdom does not come from above but is earthly, natural and demonic. For where there is jealousy and selfishness, there is disorder and every evil practice.
Again, we are coming from the verse where Paul said Be angry and do not sin; do not let the sun go down on your anger.
Meaning, take care of sin before sin takes care of you; meaning, address it. An unrecognized sin gives the devil an opportunity. He knows that’s where to continue to hit you, since you are unaware in that area.