Martyn Lloyd-Jones writes:
The power of the devil is alarming. Our Lord says to Peter, Satan has desired to have you, that he may sift you like wheat. These are indications of his tremendous power. But perhaps the ultimate proof of the power, and the confidence, and the ability of the devil, is to be found in the fact that he did not hesitate to tempt and to attack even the Son of God himself. He approached him with confidence, with assurance, for he had defeated all others. The greatest saints, the patriarchs of the Old Testament, and prophets, had all been defeated by the wiles of the devil.
Is this discouraging? I say again that it is far from discouraging. I find it to be most encouraging because now I understand what is happening. But still more, I know that the Lord reigneth. He is over all, and he has sent Someone into this world who has been able to master the strong man armed and to rob him of his armor.
Martyn Lloyd-Jones, Exposition of Ephesians (Grand Rapids, MI: Baker Books, 1998)
We must not underestimate the enemy, yet we also cannot give him to much credit. Martin Luther suggested we can mock the devil (“The best way to drive out the devil, if he will not yield to texts of Scripture, is to jeer and flout him for he cannot bear scorn”), even though I am not sure if that’s really such a great idea (doesn’t he know what is 恼羞成怒?). Anyway, the Scriptures have likened him to a strong man, who has possessions that are kept away. But there is Someone stronger who can overpower him and plunder his house.
When a strong man, fully armed, guards his own house, his possessions are safe. But when someone stronger attacks and overpowers him, he takes away the armor in which the man trusted and divides up the spoils.
And we are able to enlist the help of the Stronger One through prayer, asking Him to bind up the strong man and bundle away what are in his possession. We know that this is possible; after all, we were once people in the other kingdom.