He is not God of the dead, but of the living. (Mark 12: 27)
And Sadducees came to him, who say that there is no resurrection. And they asked him a question, saying, “Teacher, Moses wrote for us that if a man's brother dies and leaves a wife, but leaves no child, the man must take the widow and raise up offspring for his brother. There were seven brothers; the first took a wife, and when he died left no offspring. And the second took her, and died, leaving no offspring. And the third likewise. And the seven left no offspring. Last of all the woman also died. In the resurrection, when they rise again, whose wife will she be? For the seven had her as wife.” Jesus said to them, “Is this not the reason you are wrong, because you know neither the Scriptures nor the power of God? For when they rise from the dead, they neither marry nor are given in marriage, but are like angels in heaven. And as for the dead being raised, have you not read in the book of Moses, in the passage about the bush, how God spoke to him, saying, ‘I am the God of Abraham, and the God of Isaac, and the God of Jacob’? He is not God of the dead, but of the living. You are quite wrong.” (Mark 12: 18-27)
The Sadducees acknowledged only the Pentateuch, the first five books of the Bible. They did not believe in the resurrection of the dead. However, Jesus quotes a passage from Moses's calling: Moses is called by the God of the patriarchs Abraham, Isaac and Jacob, all who had long been deceased at that time. Lord, help us always remember that whoever believes in You lives forever. Help us to never forget that You rose so that we too one day may rise from the dead.