Why can't it be like a death row inmate who is incarcerated (dead in his sins but able to be influenced through the bars by the unincarcerated) and rightly condemned to death. The Governor has the authority to pardon the inmate and set him free. However the inmate still has a choice to accept the pardon or refuse it. Being a perfect Gentleman, the Governor will allow the man to go to his death if he rejects the pardon.
As with Moses and the brass serpent, the individuals that were bitten could refuse to look at the brass serpent, which would lead to their death. And yet the brass serpent was effective for all, not discriminating.
As with the Hebrew house during the passover. Any Egyptian who wished to save his firstborn would have done so by entering a house whose doorpost was covered by the lambs blood. The blood was not discriminating in any way, but was effective for all who chose to partake of it's covering.
The message of the Bible is that man is incapable of doing anything to get himself out of the pit of sin. Only God can save him by His grace through faith in Jesus Christ.
The entire Old Testament speaks to man's inability to save himself.
The New Testament, the New Covenant, tells us that from before the foundation of the world God has purposed that Christ, God Himself, would become the sacrifice for the sins of the elect, and thus man, dead in sin, can only be resurrected exactly the same way Christ was resurrected, by the hand of God.
"Can the Ethiopian change his skin, or the leopard his spots? then may ye also do good, that are accustomed to do evil." -- Jer. 13:23
"What shall we say then? Shall we continue in sin, that grace may abound? God forbid. How shall we, that are dead to sin, live any longer therein? Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. For he that is dead is freed from sin." -- Romans 6:1-7
"He came unto his own, and his own received him not. But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God." -- John 1:11-13
Born again by the will of God alone.