We use coffins no longer, yet process the body into form of dehydrated ash that can be scattered in nature. The water returns to the ocean, the matter returns to our Earth, the spirit returns to our creator. Death is renewal in so many ways.
I wonder if the term coffin comes from origins such as "cough-in," for once the plagues and influenzas took so many that a cough frequently signified the end. I wonder too if "fin" as French for "finish," is part of the word. Perhaps we need to end this word altogether and simply let the body pass back into nature without causing harm to trees or taking up tracts of land with the dead, with cut stones and engraving. It seems so bizarre to try to bring a sense of permanence when what we are coming to terms with is the concept of change and renewal, of rebirth and passing on.
When the soul is heaven-bound the body must return its matter to Mother Earth. For as Earth has nurtured us in life, we give back to her upon our passing. As such the coffin was simple cloth, no longer the wood of yesteryear. The body returns to nurture root and grass, and so this way is more respectful to creation.
The coffin was simple and neat, eco-friendly and modest. As in life, as in passing on.