1 Corinthians 15:37-38
And what you sow is not the body which is to be, but a bare kernel, perhaps of wheat or of some other grain. But God gives it a body as he has chosen, and to each kind of seed its own body.
Humans are the only creatures to have funerals. They demonstrate more clearly than any other activity the deeply human intuition that our bodies matter and are not just disposable Tupperware containers for some gassy spirit. We do not fling our beloved dead into trash compactors or dump them in a land fill. When these outrages are performed on the dead they are recognized as outrages. Why? Because the body–even the dead body–is sacred and must be handled with the same reverence as we handle the Eucharist. To be sure, what is planted in the earth is a natural seed and will pass away. But it will not pass into oblivion. It will, we have the highest assurance, be raised as Christ was raised: to participate–bodily–in the life of the Blessed Trinity. That is why Catholics “celebrate” funerals.