The only "free-will" natural man has is willful blindness (Deut 29:4, Rom 3:11-20), so it is not "free-will" that we need but mercy ... mercy to disarm and deliver us from our inflexible, obstinate, fortified self-will and its captivity to sin and the Devil. (John 8:34-36, 2 Tim. 2:26; Rom. 9:16).
Unbeknownst to many modern Christians, this was a foundational principle in the Reformation. With this same idea in mind, Luther in his "Bondage of the Will" said,
"I frankly confess that, for myself, even if it could be, I should not want "free-will" to be given me, nor anything to be left in my own hands to enable me to endeavour after salvation; not merely because in face of so many dangers, and adversities and assaults of devils, I could not stand my ground ; but because even were there no dangers. I should still be forced to labour with no guarantee of success.¦ But now that God has taken my salvation out of the control of my own will, and put it under the control of His, and promised to save me, not according to my working or running, but according to His own grace and mercy, I have the comfortable certainty that He is faithful and will not lie to me, and that He is also great and powerful, so that no devils or opposition can break Him or pluck me from Him. Furthermore, I have the comfortable certainty that I please God, not by reason of the merit of my works, but by reason of His merciful favour promised to me; so that, if I work too little, or badly, He does not impute it to me, but with fatherly compassion pardons me and makes me better. This is the glorying of all the saints in their God." - Martin Luther, The Bondage of the Will (Grand Rapids: Revell, 1957), 313-314.
After the fall of Adam all men are willfully blind and captive to sin, so left to themselves, no one willingly heeds the call to faith and repentance in Jesus Christ (Deut 29:4, Rom 3:11-20; John 3:19). But God is not content to leave everyone to their self-will, so in mercy, He saves a people for Himself out of the mass of ill-deserving sinners by giving them a new heart (Deut 30:6; Ezek 36:26; John 6:63) that they might come to faith in Christ and be saved. (also read Ephesians 1:3-5, John 6:63, 65, 37, Roman 9). The others he leaves to their own choice. So men either get justice or mercy in this world, but no one gets injustice.
So again, who will deliver us? It is God and God alone who in His infinite mercy in Christ redeems us. He does it all (1 Cor 1:30-31, John 6:63). He is the only Savior, alone sufficient in our salvation. We supply nothing but the sin to be saved from. Even more critical than justification by faith alone, is salvation BY GRACE alone ... a complete distrust of all human works and dependence on the grace of Christ alone.. Free-will cannot and will not lift a finger towards its own salvation. Supernatural intervention is needed. That is why, when Peter confesses Jesus to be the Christ, Jesus declares “Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven." (Matt 16:17)
Lord rescue me from myself.
"Men are indeed to be taught that the favour of God is offered, without exception, to all who ask it; but since those only begin to ask whom heaven by grace inspires, even this minute portion of praise must not be withheld from him. It is the privilege of the elect to be regenerated by the Spirit of God, and then placed under his guidance and government." - John Calvin, Institutes II.III