Also you failed to address the fact that those Christ died for have been reconciled to God while they are unbelievers, which shows they benefited from the Death of Christ as unbelievers, now please address that fact !
All those reconciled to God by the Death of His Son, even while they were experientially being enemies in and of themselves by nature, even children of wrath as others by nature, yet through being reconciled to God, and accepted in His Favor, they must therefore be Perfect in His sight, because God accepts no one or thing less than Perfection, for His Holiness demands it.
Whatever, if its not absolutely Perfect, Cannot be accepted with God ! But that Death of Christ, by which all for whom Christ died, and did reconcile to God thereby, even while being enemies, that Death of His or His Offering of Himself for them, made them Perfect before God !
Heb 10:14
14 For by one offering[His Death]
he hath perfected for ever them that are sanctified.