Reference: While this passage also owes a linguistic debt to Paul, there are important differences:
So also is the resurrection of the dead. It is sown in corruption; it is raised in incorruption: It is sown in dishonour; it is raised in glory: it is sown in weakness; it is raised in power:
It is sown a natural body; it is raised a spiritual body.
There is a natural body, and there is a spiritual body. (1 Cor. 15:42–44)
Amulek uses a similar vocabulary in contrasting death and resurrection, but Joseph Smith is not simply restating Paul. Both Paul and Amulek use contrasting terms: natural/spiritual (Paul) and temporal/spiritual (Amulek). But those contrasts refer to completely different concepts. For Amulek the temporal/spiritual contrast deals with the difference between resurrection and the atonement for sin. For Paul, the natural/spiritual refers to two bodily states: mortal and resurrected. While the language may be similar, the concepts encoded by that language are very different.