Jumping back on the coaster...
Death is not natural to creation, not as principle, not as biological fact. it is a foreign body, a parasite, a shadow. It is absence and negation.
We need to let our faith guide us here:
What is man? Man is a unity of Soul and Body, he is literally Psychosomatic (Psyche-Soma, soul-body). The holy fathers and our faith CLEARLY teaches us that our highest goal is Theosis, attainment of unity with Christ through participation in him by grace (The uncreated divine power of God), this union is both spiritual, and BODILY. In the resurrection, we will receive a new body which replace this mortal body subject to death and decay. But if that is the case, then we must also assume that our CURRENT mode of existence, as a Soul hypostatically united to a body subject to corruption is FOREIGN. Also, the human soul existing in paradise, although blessed and ecstatic is in an UNNATURAL condition. The soul was not created to be ABSENT from the body, but to ANIMATE a body, meaning, since purpose is what determines nature, that a discarnate soul is living in a state contrary to nature. Therefore PHYSICAL DEATH is unnatural, MEANING it came about only through an alteration of the original course of nature; but there is no purely natural force or merely physical event that could cause a spiritual rupture in man, therefore this event must be a fundamentally spiritual event that fundamentally altered the nature of the Soul's relation to the body, therefore inviting into the material world:
Mankind handed dominion over nature to the devil, so that until the Incarnation of the Logos, he was the god of this world as the scripture teaches.