Among his notes, C. H. Spurgeon tells of an imaginary conversation on the topic of "Free Will":
"Do you see the cat? She sits there, and will lick her paws and keep herself clean." "I see that," said the other. "Well," said the first speaker, "Did you ever hear of one of the hogs taken out of the pigsty that ever acted like the cat?"
"No," he said. "But he could if he wanted to," said the other.
"Yes! truly he could if he wanted to; but it is not according to his nature, and you never saw such a thing done, and until you have changed the swine's nature, he cannot perform such a good action, and God's Word says the same thing of man."
"And you were dead in your trespasses and sins, in which you formerly walked according to the course of this world, according to the prince of the power of the air, of the spirit that is now working in the sons of disobedience. Among them we too all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest." (Ephesians 2:1--3)
In the Bible, death indicates separation, such as the spirit separating from the body. In this passage Paul is rehearsing truths related to the Ephesian Christians' pre-salvation days, in which they were separated by their sinful nature from the spiritual life of Christ. Common to all who are spiritually dead in trespasses and sins, both then and now, their nature was at enmity with Christ, with the desires of both the flesh and the mind being hostile toward Him. Given a choice, (much like the crowd when presented with the Lord Jesus and Barabbas), the one whose will is in bondage to sin always chooses someone other than Christ.
What is required for someone to be able to choose the Lord Jesus? The Lord Himself said, "You must be born again." How? Look to the Lord Jesus. He is faithful. He hears, knows and saves, perfectly.
You'll discover the ability to do what you ought... and that's a truly free will.