A commonly taught principle relevant to God’s purpose for man is that he is endowed with free will. It is said that man is a free moral agent, meaning he possesses unrestricted power in making moral choices.Indeed, how could God possibly have designed man devoid of the power of choice? He had to give him the ability to choose—not merely between right and wrong, but more importantly choice in regard to the lordship of God over his life.

Yet what appears on the surface to be the ability to choose freely, is in a very real sense something more than merely free will. 

Man’s rejection of God as Lord of his life does not in any way mean that he possesses the ability of free choice in regard to everything else. Rather, in refusing to accept God’s purpose and plan for his life, he inevitably opens himself up to control by some other outside force.  And this force is ultimately Satan. But the tool the devil uses to subjugate mankind is man’s will—a will inherently rooted in self-interest. So we should instead think of this self-serving attribute of man’s nature—what we commonly call free will—as self-will.

Excerpted from: Free from the Power of Sin: The Keys to Growing in God in Spite of Yourself