Job 2:6

And the LORD said unto Satan, Behold, he is in thine hand; but save his life.

He is delivered into power to be afflicted in body, yet under strict command that life be spared, so real power to harm is granted within a boundary that cannot be passed. This permission answers the scornful charge that fear was for nothing and was shown only because a hedge had been set around him and all he had, and that if possessions and then bone and flesh were touched he would curse to the face, making bodily affliction the test of disinterested obedience. In that permitted trial there is anguish and the feeling as though the divine hand has touched, yet faith and the sense of integrity are held fast. The suffering does not come from a sinful course of life, and loyalty remains amid losses and illness and false accusations from friends.

The destroyer is restrained by divine protection and can afflict people only within what is allowed. When that protection is withdrawn trouble can be brought upon them, though they may wrongly suppose that God Himself is causing the affliction. The same limit holds where affliction is permitted but a boundary is set so that life may not be taken, as with James. So too strange behavior in a child may be the work of Satan or his evil angels, but prayer rebukes the enemy's power so that the affliction ceases.