10 For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life.
Those whom Christ by His Death alone, reconciled to God, even while unbelieving enemies, much more, they whom are so reconciled as enemies, shall be saved by His Life, their eternal salvation is secured.
These also whom are reconciled to God while enemies/unbelievers, Christ not only died for them as such, but rose again and is in heaven making intercession for them, even while unbelieving enemies. Rom 8:34
34 Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.
So we know by this that Christs death has limited effects, and wasn't for all men, those who are never saved !