Christ vs. the Sadducees on the Resurrection

"What is the issue here? The issue is whether or not there is a resurrection of the dead. “The Sadducees, who say that there is no resurrection,” were arguing, by presenting Jesus with this preposterous hypothetical, that there cannot really be a resurrection of the dead.

Mark introduces the incident with the same explanatory theological note on the Sadducees: “Then the Sadducees, who say there is no

resurrection, came to Him with a question.” Mark 12:18. 

As does Luke: “Some of the Sadducees, who say there is no resurrection, came to Jesus with a question.” Luke 20:27. Obviously, the only issue in this passage is whether or not there will be a resurrection of the dead.
By asking, “whose wife will she be in the resurrection,” the Sadducees thought that they had asked an unanswerable question and had thereby proved the doctrine of the resurrection to be unworthy of belief. Christ exploded the hypothetical by declaring, "In the resurrection they neither marry, nor are given in marriage."

Jesus then proceeded to the real issue, the resurrection of the dead: "But as touching the resurrection of the dead, have you not read that which was spoken unto you by God, saying, I am the God of Abraham, and the God of Isaac, and the God of Jacob? God is not the God of the dead, but of the living." Matt. 22:31-32.

Again, the only issue in this passage is whether there will be a resurrection of the dead, and a resurrection of the dead is necessary only if the dead are sleeping in the grave. 

Jesus is defending the doctrine of the resurrection from skeptical Sadducees, who, Scripture tells us in several places, did not believe what Scripture teaches regarding the resurrection." 

F.D. Nichol