He is not God of the dead, but of the living.
There came to him some Sadducees, those who deny that there is a resurrection, and they asked him a question ... And Jesus said to them, “The sons of this age marry and are given in marriage, but those who are considered worthy to attain to that age and to the resurrection from the dead neither marry nor are given in marriage, for they cannot die anymore, because they are equal to angels and are sons of God, being sons of the resurrection. But that the dead are raised, even Moses showed, 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 not God of the dead, but of the living, for all live to him.” Then some of the scribes answered, “Teacher, you have spoken well.” For they no longer dared to ask him any question.
Jesus spent his last week on earth doing in Jerusalem what he did in other places - namely teaching and preaching about the nature of the kingdom of God. Yet the Sadducees, like many today, could not understand how a person's life could possibly transcend death. Their ignorance resulted from a focus on the earthly kingdom and not the heavenly one.. what is seen rather than things unseen. Many today still believe the error of the Sadducees.
And some, even today, think that the new birth, taught by Christ to Nicodemus the Pharisee, is a concept limited to the New Testament. These would do well to hear the words of Jesus in this passage. Abraham, Isaac and Jacob are alive today even though their flesh died many years ago. Moses and Elijah appeared on the Mount of Transfiguration and were recognized by the disciples. We who have been born of the Spirit are like these in that our lives will survive death.
How can I express my joy Lord? Knowing that I will be with you forever astounds me and thrills me to the core.