Why does Paul quote Isaiah 22:13?

Paul writes, “Let us eat and drink, for tomorrow we die” (1 Cor. 15:32), which is a citation of Isaiah 22:13. Why does Paul cite this OT passage?

The context of Isaiah 22:13 is the coming judgment of God (Is. 22:14). In this context, people are flippantly carrying on with life, as though there is no judgment (“There is gaiety and gladness, killing of cattle and slaughtering of sheep, eating of meat and drinking of wine”). If God is really coming to judge, then the people should be repenting of their sin (Is. 22:12). However, the people don’t seem to care. In this context, the people say, “Let us eat and drink, for tomorrow we die” (Is. 22:13).

Paul cites this passage to make his point about the resurrection of the dead. In a sense, he turns Isaiah’s argument on its head. Isaiah was saying, “It’s insane to go on eating and drinking, as though nothing is wrong, when judgment is right around the corner.” Paul argues just the opposite to make his point about the resurrection. He is basically saying, “If there is no resurrection (and no judgment), then we might as well go on eating and drinking… Why wouldn’t we?”