Physical Death

God created man in His image and in His likeness.  He placed man (Gen 1:27) in the Garden of Eden for a time.  We call this time a probationary period.  God gave instructions to be followed.  He also gave man the right to make choices, but made man accountable for these choices.
Man was created of body (which is temporal) and Spirit (which is eternal).  Death is the time of separation of the temporal (body), which goes back to the earth, and the Spirit, which goes back to God for a temporary judgment.

(1Cor 15:21-22) For since by man came death, by man came also the resurrection of the dead.  For as in Adam all die, even so in Christ shall all be made alive.

(1 Cor 15:44 ) It is sown a natural body; it is raised a spiritual body.  There is a natural body, and there is a spiritual body.