The Sadduccees were the priestly aristocracy and the wealthy landowning class. Thoroughly conservative in politics, they accepted Roman rule in Palestine and had compromised with it. In theology, they accepted only the Law as the basis of Judaism, and rejected the doctrine of the resurrection as it found no place in the Law.
The case the Sadduccees presented to Jesus was meant to illustrate the absurdity of believing in the resurrection, in an after-life. It refers to the levirate, a custom in many tribal societies, of raising children in the name of a deceased family member. If a married man died without issue, his brother was obliged to raise a child through his widow in the name of the deceased, before raising his own children. Therefore, the Sadduccees jibed: in a case where the woman had multiple spouses in this life, whose wife would she be in the after-life ?
Jesus answers the question by denying the presupposition that marriage endures in the after-life. The resurrection is affirmed, yes; but a transformation of the body is also affirmed. This transformation makes individuals “like angels” – they have no need of marrying, nor are they subject to death.
The question of ‘what kind of body’ will the resurrected possess certainly troubled the early Christians. Would it be a physical body, like our present one, with the blemishes removed? Paul the apostle – who may have influenced Luke – calls it a “spiritual body”, and his metaphor is that of a seed, and the plant which grows out of it. The plant is superior to the seed in many ways, so will it be with us. The resurrected state is different and superior to our present mortal life.
Jesus alludes to the passage in the book of Exodus, where God speaks to Moses from the burning bush. Yahweh says that he is “the God of Abraham, Isaac and Jacob”, patriarchs who had died centuries ago. If, there were no resurrection, there would be no patriarchs either – they’d be dead and gone. But, argues Jesus, God refers to them as existing, as children of the resurrection, “for he is God not of the dead, but of the living, for to him all are alive.”