We have died to the Law by being baptised into Christ's death.
This you said earlier - "If Universalism is true Jesus did not have to die." Yet every single one of us who is saved is baptised into His death. He, through death, conquered death. He, God incarnate, the Word made flesh, died as a man, without sin, and rose triumphant from the grave.
"O Death, where is your sting? O grave, where is your victory?"
So, I would say, that only through the death and resurrection of Jesus Christ would universalism even be possible (not that I am arguing in favour of it, only demonstrating the incomparable power of the resurrection) because it is only though Christ, God the Son made man, come into the world as the New Adam who conquered death, that the old Adam can be saved.
So, the reason we are dead to the law, is the reason that we hope in resurrection.
Therefore, since we have such hope, we use great boldness of speech — unlike Moses, who put a veil over his face so that the children of Israel could not look steadily at the end of what was passing away.
But their minds were blinded.
For until this day the same veil remains unlifted in the reading of the Old Testament, because the veil is taken away in Christ.
But even to this day, when Moses is read, a veil lies on their heart. Nevertheless when one turns to the Lord, the veil is taken away.
Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty. But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as by the Spirit of the Lord.
2 Corinthians 3:12-18