V.29-30 These verses don’t mean to be baptized for a person who had already died. What they do mean is that baptism signifies identifying myself (as well as all those who have already died believing) with the death of Christ. If there be no resurrection, what would be the use of becoming a Christian? If the dead don’t rise (v. 16) then those believers who had died have perished. Baptism in those days was so serious an act that those who did get baptized put themselves in a position where they might be murdered at any moment. Like giving yourself up for dead.
V.33-34 Satan was introducing these lies to cause people to indulge in evil.
V.35-36 Paul describes these thoughts as foolish.
V.37-44 The body that has been redeemed is the body that shall be raised, although changed to a glorified body fit for heaven.
V.45-49 The first Adam and the last Adam (Christ) are contrasted, also the earthly with that which is heavenly. We believers are now like our Head, we are heavenly.
V.50-54 The mystery is explained. Read 1 Thess. 4:13-18 — the coming of the Lord for us believers. In an army, the last trumpet was the one that set them in motion.
V.55-58 If this truth takes a hold of us, it makes us diligent in serving the Lord.