Christ did so much more than dying for sin and making Salvation possible or available to all mankind, thats such a false teaching, However what He did do for them He died for, Gods Elect, He absolutely redeemed them from the curse of the Law Gal 3:13
13 Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree:
Thats Salvation, for sin finds its curses because of the Law 1 Cor 15:56
The sting of death is sin; and the strength of sin is the law.
The law nor sin can condemn any sinner Christ died for.