Paul next addressed the objection that the resurrection of the body is impossible because when a person dies his or her body decomposes and no one can reassemble it. The Corinthians seem to have wanted to avoid thinking that the material body was essentially good. Hellenistic dualism seems to have influenced their thinking about the human body and, therefore, the resurrection. Dualism is the philosophy, so common in pagan Greek thought, that the body is only the husk of the real "person" who dwells within. The more one can live without the constraints that the body imposes the better. The biblical view, on the other hand, is that the body is essentially good and just as much a part of the real "person" as the immaterial part (cf. Genesis 2:7). The original readers did not, and most people do not, view very positively a resurrection that involves simply resuscitating human corpses. Paul proceeded to show that the resurrection of believers was not that but a resurrection of glorified bodies. Paul taught a more glorious future for believers than the present "spiritual" existence that some in Corinth lauded. [source][source][source]
"The Corinthians are convinced that by the gift of the Spirit, and especially the manifestation of tongues, they have already entered into the spiritual, "heavenly" existence that is to be. Only the body, to be sloughed off at death, lies between them and their ultimate spirituality. Thus they have denied the body in the present, and have no use for it in the future." [1][source]
"Dead" (Gr. nekros) appears11times in 1 Corinthians 15:1-34 but only three times after 1 Corinthians 15:34. This indicates a shift in Paul"s argument. [source][source][source]