It is important to say a little about the Sadducees. They were a small part of the Jewish community who did not believe in the afterlife. (And that is sad you see!) Their reason for this was that it was not in the Bible. All their beliefs were based on a literal interpretation of the Torah, i.e. the first five books of the Bible. If it wasn’t there, it wasn’t true.
We know there are many references to life after death in the O.T. (Maccabees), but for the Sadducees the reference had to be in the Torah. In this confrontation with the Sadducees, Jesus is the first Rabbi to prove from the Bible (Torah) that afterlife is revealed by God; God is the God of the living; “for him in fact all people are alive”.
This was a theological defeat for the Sadducees. They did not survive the attack.
Let us look at the text. The ridiculous example of many marriages is meant to confront Jesus with an impossible situation. It is a challenge to his theology of Resurrection. Jesus quickly brushed off the objection. Heaven is not about marriage. “Those who are judged worthy of a place in the other world and in the resurrection of the dead do not marry”. Jesus again mentions the resurrection. “….being children of the resurrection they are sons of God”. By twice mentioning the “resurrection” word, Jesus is about to challenge the basis of their Theology. He produces in Rabbinic style, a scriptural reference from the TORAH, (Exodus 3.6) to prove the existence of an afterlife. They all know the story of the Burning Bush. They all know the reference that Jesus produces. The argument is over for ever. Signed, sealed and delivered.
“And Moses himself implies that the dead rise again in the passage about the bush, where he calls the Lord the God of Abraham and the God of Isaac and the God of Jacob. Now he is God, not of the dead but of the living. For to him all men are alive”. In Rabbinic Law, there is no greater authority than Moses.
“I am the resurrection and the life. He who believes in me will never die”.