“Why anyone would “preserve dead body parts” and display them for worshi...”
Pagan practice, with ncorporated under Rome and now claimed as tradition.
At one time, 18 different churches claimed to have the foreskin of Jesus’ circumcision as their relic.
My favorite is the church that claims to have the mother’s milk of Mary.
An example of such a relic would be NEHUSHTAN.
Made:
Numbers 21:8
Then the LORD said to Moses, “Make a fiery serpent, and set it on a standard; and it shall come about, that everyone who is bitten, when he looks at it, he will live.”
Numbers 21:9
And Moses made a bronze serpent and set it on the standard; and it came about, that if a serpent bit any man, when he looked to the bronze serpent, he lived.
Destroyed:
He removed the high places, smashed the sacred stones and cut down the Asherah poles. He broke into pieces the bronze snake Moses had made, for up to that time the Israelites had been burning incense to it. (It was called Nehushtan.)
I believe it was National Geographic, many years ago, said, with the fall of Constantinople in the 4th Crusade, 1204 AD, among of the relic loot were THREE heads of John the Baptist.