"Art thou the Christ? tell us. And he said unto them, If I tell you, ye will not believe."
The Most Horrible of all Sins
If I understand the Word of God, the greatest, most abominable evil in this world is the horrible sin of unbelief. I would rather stand before God guilty of any crime known to man than stand before him guilty of having heard and refused to believe the gospel of his dear Son. Why? Because unbelief is man's willful declaration that God himself is a liar (1 John 5:10). Unbelief is the most daring and the most obnoxious evil in the world. Yet, unbelief is as natural to man as spots on a leopard. Unbelief is the bent of the human will.
A Deliberate Act of the Will
Yes, unbelief is an act of the will. Our Lord said, "Ye will not believe." Both faith and unbelief involve the will. I know that faith is the gift of God, effectually wrought in his elect by the Holy Spirit. And I know that no man can, by nature, believe God. But I also know that believing is an act of the will. No one believes without willing to believe. Faith is God's gift wrought in us, not upon us. He works in us both to will and to do of his good pleasure. God gives us the will to believe. Yet, faith is a voluntary thing. If I believe God, I do so willingly. And unbelief is a voluntary thing. If you refuse to believe God, you do so voluntarily, you choose to do so. Your unbelief is your own fault. It is a crime for which you must bear all blame and guilt.
A Refusal to Acknowledge Sin
Why do men and women refuse to believe God? The fact is, unregenerate men and women prefer to embrace and trust any form of darkness to believing the revelation of God. How readily man receives the changing speculations of science, myths of mysticism, and opinions of "learned" men. Man prefers feelings to faith. Therefore, emotional religion is appealing. Men prefer faith in themselves to faith in Christ. Therefore, free-will, works religion is attractive. Men prefer visions, signs, miracles, and experiences to divine revelation. Therefore charismatic religion is accepted. And men prefer the pretense of intellectualism to the simplicity of faith. Therefore intellectual religion, whether liberal or conservative, Arminian or Calvinistic, is applauded.
Why do men and women refuse to believe God and the gospel of his free grace in Christ? The answer is simple. -- Faith in Christ begins with an acknowledgment of personal sin, depravity, guilt, and inability. No unregenerate man will make such an acknowledgment. His pride, self-righteousness, and love of self keep him from believing God.