What does Luke 20:28 mean?
The Sadducees are a Jewish sect that follows the Mosaic law and does not believe in the resurrection of the dead (Luke 20:27). Their representatives are trying to catch Jesus in a theological paradox. It is days before the crucifixion, and Jesus is teaching in the temple court. Pharisees, lawyers, and chief priests have already tried to discredit Him by presenting unanswerable puzzles. All of them have failed (Luke 20:1–26).Their "question" is really a challenge which supposedly demonstrates the absurdity of resurrection. Attempting to prove that Jesus is not a good spiritual authority, the Sadducees ask about the tradition of levirate marriage with respect to resurrection of the dead. Levirate marriage was a common cultural practice found in the Mosaic law (Deuteronomy 25:5–6). Land, along with fertility, was one of God's greatest blessings to the Jews. Inherent in the possession of land was the continuation of a man's genetic line.
The most detailed example of levirate marriage is found in the story of Judah and Tamar (Genesis 38). Judah, one of Jacob's sons, gave his daughter-in-law to a younger brother when the older son, her husband, died. That son died also, and neither had produced an heir. Judah refused to give his third son to Tamar; he claimed to be waiting for the son to mature. Tamar quickly realized this was a lie. Eventually, she tricked Judah into impregnating her, and he admitted he had not treated her fairly.
The Sadducees present a similar situation about a woman who legitimately married multiple men prior to her own death. In their heightened example, a woman consecutively marries seven brothers and still has no sons. The Sadducees will eventually ask, "In the resurrection, therefore, whose wife will the woman be?" (Luke 20:33).