From Anthony Coletti:
If God wanted everyone to be saved, then they would be saved, or God's will is not sufficient to save everyone. Then God is not omnipotent. Or possible, God's will is passive, and mans' will rules over God's.
For if God is omnipotent and omniscient, then whoever God wills to be saved, will be saved. And clearly God knows every hair on your head, and no harm comes to those whom he calls to be his children.
If faith was an act of mans' will, then the final cause of salvation is up to man, and not God. But faith is a gift of God, purely by God's grace and will, not by mans willing and running after. Unregenerate man does not seek after God. Unregenerate man has no desire for God.