What does 1 Corinthians 15:44 mean?

This part of Scripture lists ways in which a Christian's earthly body is drastically different from our resurrection body. We will have something entirely different when Christ returns for those who belong to Him. So far, Paul has described that new body as being eternal, rather than temporary (1 Corinthians 15:42), glorified, rather than dishonorable (1 Corinthians 15:43), and powerful, instead of weak (1 Corinthians 15:43).

Now he adds that the born-again believer's earthly form is "sown" as a natural body (1 Corinthians 15:37), but will be raised as a "spiritual body." The current body is made from nature, in the sense that Adam's body was molded from clay (Genesis 2:7). Our naturally-born frames are "of the earth" and cannot exist in the realm of eternity. The spiritual body revealed by the resurrection is made of the stuff of heaven, so to speak. It exists easily in eternity.

It's important to note that the word "spiritual" as used here does not mean the "spiritual body" has no physical shape or form. Paul has not followed the idea of resurrection all the way back to the idea of existing as mere spirits for eternity. He's attempting to explain something profound in simple terms. The resurrection body is "spiritual" in the sense that it fits into the spiritual / heavenly realm while still having a solid, physical form. Jesus' body after the resurrection is an example of this. He could be seen, heard, and touched (John 20:24–29), and He could eat (Luke 24:36–43). He could also, apparently, move through solid objects (John 20:19). He had been raised into His spiritual, glorified body.