The Body is Holy
To the Orthodox, a human being is an integrated body and soul. As such, at physical death the separation of the soul from the body is not a natural occurrence; rather, it is abnormal. Therefore, after death, the body remains a holy vessel, a temple that was and will be again inhabited by the person’s soul and by the Holy Spirit. Also, the body is commingled with the body of Christ in the most literal sense; having partaken of the Holy Eucharist, the body and blood of Christ are part of the body of the deceased—in the organs, muscles, bones…all of the cells of the body.
In sacrament, the transcendent enters into the immanent; heaven and earth are united in such a way that they stop existing in their separateness and oppositeness.
—”On Holy Relics,” by Fr. Sergius Bulkagov
The Orthodox Church teaches that the bodies of those in Christ are to be regarded as sanctified by the hearing of the Word and faithful participation in the Sacraments, most particularly the Holy Eucharist; because of the indwelling Holy Spirit the consecrated bodies of Christians do not belong to them but to Christ; with respect to the indwelling Holy Spirit there is no difference between the bodies of Christians before and after death; whether before or after death, the Christian body is also to receive the same veneration; and notwithstanding the physical corruptions that the body endures by reason of death, there remains a strict continuity between the body in which the Christian dies and the body in which the Christian will rise again. That is to say, it is the very same reality that is sown in corruption and will be raised in incorruption.
—”The Commerce of Human Body Parts: An Eastern Orthodox Response,” by Fr. Patrick Henry Reardon