Have you ever noticed the overtones of spiritual battle in the New Testament letters to the churches? Words like enemy, battle, weapons, conflict, and evil? Peter, James, John, and Paul warned their readers about the kingdom of darkness.
Be alert and sober of mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. (1 Peter 5:8)
So submit to [the authority of] God. Resist the devil [stand firm against him] and he will flee from you. (James 4:7 AMP)
We know that anyone born of God does not continue to sin; the One who was born of God keeps them safe, and the evil one cannot harm them. We know that we are children of God, and that the whole world is under the control of the evil one. (1 John 5:18–19)
God is strong, and he wants you strong. So take everything the Master has set out for you, well-made weapons of the best materials. And put them to use so you will be able to stand up to everything the Devil throws your way. . . . This is for keeps, a life-or-death fight to the finish against the Devil and all his angels. (Ephesians 6:10–12 MSG)
The New Testament Scriptures are full of such language, of exhortations and admonishments to “be careful,” “pay attention,” and “be courageous.” The friends of Jesus knew. How did they come to know? Through experience. Through receiving first hand teaching from Jesus, then watching Jesus encounter the enemy (i.e., demons), then experiencing their own encounters. This is how we too are to learn discernment and how to wield power and authority, enforce the kingdom’s ways, defend against the opposition, and free those under the enemy’s influence.