William Burkitt on 1 John 5:19

That is, the far greater part of the world are under the dominion of that wicked one, being sunk into idolatry, and become worshippers of the devil, continuing in the midst of their impurity and malignity, and wholly set upon mischief and wickednes.

See here the darkness and horror of an unregenerate and unconverted state. Persons in it are under the dominion of Satan, that wicked one. But behold the blessed change that Christianity makes, not in the profession, but in the practice of it, it delivers from the power of darkness, and from the power of Satan, the prince of darkness, and translates us into the kingdom of God's dear Son.