- - - - - - - - - -It is also important to point out that the Second Person of the Trinity remained hypostatically united to the body while it remained in the tomb for three days. The Apostles' Creed says, that the Son of God "was conceived and born of a Virgin, suffered, died, and was buried." Hence, St. Thomas Aquinas points out that what is true of the body (that it is buried) is predicated of the Son of God by the creed.
Aquinas goes on to explain that "What is bestowed by God's grace is never withdrawn except through fault." The grace of union of the flesh with the Divine Person is a far greater grace than the grace of adoption by which we are sanctified (and which we can lose through sin). But Christ does not sin, and therefore the union of his flesh with his Divine Person cannot be lost because of a fault.
Christ assumes the whole human nature--body, blood, and soul--in his person (hypostasis). This is in line with Chalcedon's definition that the two natures are united in one person "without confusion or change, without division or separation." Once united, nothing can separate the union with the human nature, not even death.
Even though the soul was the means of the divine union with the body, Aquinas goes on to say, "The Word of God is said to be united with the flesh through the medium of the soul, inasmuch as it is through the soul that the flesh belongs to human nature, which the Son of God intended to assume; but not as though the soul were the medium linking them together. But it is due to the soul that the flesh is human even after the soul has been separated from it--namely, inasmuch as by God's ordinance there remains in the dead flesh a certain relation to the resurreciton. And therefore the union of the Godhead with the flesh is not taken away." In a Christian perspective, a dead human body remains "human" because it is ordered to the resurrection.
What this means is that the dead body in the tomb is not simply a carcass awaiting reanimation, but rather remains intrinsically united to the Divine Person, who, at the same time, united to his human soul descends into Sheol.