The "free gift" is physical resurrection. Even unbelievers will be raised. In Adam all die, and in Christ, all will be raised. Ever wonder why Romans 5:18-21 uses such universal language? Because it's not speaking of someone being dead spiritually, or born again spiritually. Compare the wording of Romans 5 to 1Corinthians 15:20-23. And Paul is clearly in the context of physical death and resurrection on 1Cor 15. Here in Romans 5 the same.
Ever wonder why Paul used such confusing language in 5:9-10? Having been justified by His blood, having been reconciled, we shall be saved by His life.
Justified by His death, saved from physical death by His resurrection. He's the first fruits, and we will all follow. We cannot help our physical relation to Adam. We are all condemned to die physically because of that rascal.
But spiritual death? That's on you. And that's on me. We can't pin that on Adam. Romans 1-2 make it very clear that you and I are without excuse. How can someone become a fool if he was born a fool? How can someone acknowledge God no longer if he never did in the first place? How can one exchange the glory of God for an image it he was born not acknowledging God in the first place?
