Albert Barnes Commentary 1 Corinthians 15:39

"All flesh is not the same flesh: but there is one [flesh] of men, and another flesh of beasts, and another flesh of birds, and another of fishes." — 1 Corinthians 15:39 (ASV)

All flesh is not the same flesh. This verse and the following are designed to answer the question from 1 Corinthians 15:35: with what bodies do they come? The argument here is that there are many kinds of bodies; that all are not alike; that while they are bodies, they yet partake of different qualities, forms, and properties. Therefore, it is not absurd to suppose that God may transform the human body into a different form and cause it to be raised up with somewhat different properties in the future world.

Why, the argument is, should it be regarded as impossible? Why should it be held that the human body may not undergo a transformation, or that it would be absurd to suppose it may be different in some respects from what it is now? Is it not a matter of fact that there is a great variety of bodies even on the earth? The word flesh here is used to denote body, as it often is (1 Corinthians 5:5; 2 Corinthians 4:11; 2 Corinthians 7:1; Philippians 1:22, 24; Colossians 2:5; 1 Peter 4:6).

The idea here is that although all the bodies of animals may be composed essentially of the same elements, God has produced a wonderful variety in their organization, strength, beauty, color, and dwelling places—such as the air, earth, and water. It is not necessary, therefore, to suppose that the body that will be raised will be precisely like the one we have here.

It is certainly possible that there may be as great a difference between that body and our present body as there is between the most perfect form of the human frame here and the lowest reptile. It would still be a body, and there would be no absurdity in the transformation. The body of the worm, the chrysalis, and the butterfly is the same.

It is the same animal still. Yet how different the gaudy and gay butterfly is from the creeping and offensive caterpillar! So there may be a similar change in the body of the believer, and yet it may still be the same.

Concerning a skeptic on this subject, we would ask: if there had been a revelation of the changes a caterpillar might undergo before it became a butterfly—a new species of existence adapted to a new element, requiring new food, and associated with new and other beings—and if this skeptic had never seen such a transformation, would it not be attended with all the difficulty that now encompasses the doctrine of the resurrection?

The skeptic would no more have believed it on the authority of revelation than he will believe the doctrine of the resurrection of the dead. And no unbeliever can prove that the one is attended with any more difficulty or absurdity than the other.