In 1983, James Wright and Peter Rossi performed a study on the effects of an armed population on crime. Surveying 1,800 convicted criminals, they found that 81% of them agreed that the smart criminal will always try to find out if his victim is armed, 74% believed burglars would rather target unoccupied dwellings to avoid encountering an armed occupant, 40% had been deterred from committing a crime because their target was armed, and a further 57% were far more afraid of an armed victim than of the police.
All of these criminals had one thing in common: A desire for an easy target. The risk/reward potential had to be skewed against risk and in favor of reward. No criminal will commit a crime if they think they will be caught or injured. Now, apply that logic to the devil, with your soul as his desired prize. Your soul is of literally infinite worth. The same God who created the Heavens and the Earth believed that to the point where He literally entered creation as a human and died to save it. But Satan wants that soul too, and he is willing to do anything to steal it. What's the solution? Arm yourself.
The Bible calls itself a sword. In Hebrews 4:12, for example, we read “For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart.”
We see a literally perfect example of this in Matthew 4. Satan, seeking to disrupt the Gospel and cause Christ Himself to sin, came to Christ at a very weak moment. Fasting 40 days alone in the wilderness, Jesus had one defence: The word of God. Satan tempted Jesus three times, and every time Jesus returned to the word of God. Finally He says “Away with you, Satan! For it is written, ‘You shall worship the LORD your God, and Him only you shall serve.’" (Matthew 4:12). What happens in verse 13? "Then the devil left Him, and behold, angels came and ministered to Him."
So Jesus, keeping with the concept described in James 4:7, resisted the Devil, and the Devil fled from Him. Why? Because Jesus had the biggest gun in all the universe: the word of God. But here's the catch: You have to know how to use it. Any physical weapon is useless unless the wielder knows how to use it. The exchange in Matthew 4 isn't as simple as pointing a gun and pulling the trigger. It's more like a sword fight. In fact, Satan himself wields the same sword. In verse 6, for example, Satan quotes Psalm 91:12. Jesus replies with Deuteronomy 6:16.
One advantage Satan has is that he is more than 6,000 years old. Job 38:7 even indicates that angels existed before, or at least during the creation of the Heavens and the Earth, so Satan may be older than that. What that means is that he is a much better Bible scholar than you. He witnessed the events first hand, has read the word many times over, and still bears the scars from battles past with other Christians who have used it against him. In other words, the only defence you have is to learn as much as you can. Absorb the word of God. Memorise verses, look at the context, watch how Satan's warriors use God's word and be prepared for when they play the same tricks on you. Most importantly, be skeptical. Take the attitude of the Berean Jews in Acts 17. “These were more fair-minded than those in Thessalonica, in that they received the word with all readiness, and searched the Scriptures daily to find out whether these things were so.” They didn't even take the words of the Apostles at face value. They took them on board and tested them with Scripture.
Don't let yourself look like an easy target. What you have, Satan wants, and wherever you lock it, he's coming for it. If you don't know the Scriptures, you might as well just leave your most valuable items on your front lawn when you go on holiday. If you study the Scriptures, your soul is guarded by a fully armored SWAT team with assault rifles. Arm yourself, do not fall prey to the evil one.