Answer from Randy Alcorn:
I still can’t get around Christ’s words in Matthew 22, which seem to clearly refute the Sadducee’s assumptions that if there were a resurrection, it would mean marital partnerships from earth would carry over to the resurrected life, and therefore people would have multiple spouses. Look at His words and consider the context:
The same day Sadducees came to him, who say that there is no resurrection, and they asked him a question, saying “Teacher, Moses said, ‘If a man dies having no children, his brother must marry the widow and raise up children for his brother.’ Now there were seven brothers among us. The first married and died, and having no children left his wife to his brother. So too the second and third, down to the seventh. After them all, the woman died.