What is "baptism for the dead" and who were "they" that were being so baptised? 1Corinthians 15:11 identifies them.
In the OT Greek [the Septuagint – LXX] this word is primarily used in describing God's "dealings" with His people.
This is the wonderful truth of our Gospel. The good news of the gospel is a life of freedom over sin – not from sin.
It is my contention that the Law was dealt its death knell through the Cross of Calvary.