“He is not God of the dead, but of the living”
I am the God of Abraham, the God of Isaac, and the God of Jacob. He is not the God of the dead, but of the living. (Matthew 22:23–32 BSB)
What it sounds like today
The seven-brothers puzzle looks bizarre, and Jesus' answer seems to dodge it.
The cultural key
The Sadducees' riddle is built on levirate marriage (Deuteronomy 25:5–6): a man must marry his brother's childless widow to raise an heir. The Sadducees, the temple aristocracy, accepted only the books of Moses as fully authoritative and denied resurrection, so their puzzle is a reductio: whose wife in the resurrection? Jesus answers from their own turf, the Torah itself: at the bush (Exodus 3:6), God says 'I am', present tense, 'the God of Abraham,' centuries after Abraham died.
Recovered meaning
God does not introduce himself by dead men's names. If he still calls himself Abraham's God, Abraham is not gone; covenant relationship outlives the grave. A resurrection proof drawn from the only scriptures his opponents fully conceded.