No MIB, that's not what it is referring to. A mortal body is a body which is already alive, liable or subject to death. You are speaking of a dead body being resurrected, Paul was speaking of a live body being infused with the life, sustained, if you will, by the Spirit of life "if that Spirit dwells in it":)
LIke I said, humanity and historical precedent dances around the point Paul was making,,,,man fearful of that which he understands not, and history recording that which appears to have always been.
Only the Holy Ghost can reveal depths of Spiritual truth, revelation knowledge from the Father to an individual.
Thank you Lord, for the voice of the Spirit, which speaks truth over all other voices,,,AMEN`