Don't know if Martin Lutehr invented it (I'll take your word for that) but I think if you read this passage from the Old Testament, you might be able to make the case that he was trying to put a Christian spin on an old (much older) pagan tradition:
"This is what the LORD says: "Do not learn the ways of the nations or be terrified by signs in the sky, though the nations are terrified by them. For the customs of the peoples are worthless; they cut a tree out of the forest, and a craftsman shapes it with his chisel. They adorn it with silver and gold; they fasten it with hammer and nails so it will not totter..."" (Jer. 10:2-4)
And please don't feel that I'm trying to tell you not to have a Christmas tree. Whatever holds meaning for you as you celebrate the birth of our Savior is fine with me. I just know that another wise man once said that "There is nothing new under the sun."
That passage is referring to creating and carving totem poles and the like for worship of lesser Gods.
For those of you wondering about the verses in Jeremiah pertaining to cutting down a tree and covering it in silver and gold, here are some other translations of those verses:
Contemporary English Version(CEV):Jer 10:2 Don't follow the customs of those nations who become frightened when they see something strange happen in the sky.
Jer 10:3 Their religion is worthless! They chop down a tree, carve the wood into an idol,
Jer 10:4 cover it with silver and gold, and then nail it down so it won't fall over.
Jer 10:5 An idol is no better than a scarecrow. It can't speak, and it has to be carried, because it can't walk. Why worship an idol that can't help or harm you?
Darby: Jer 10:2 Thus saith Jehovah: Learn not the way of the nations, and be not dismayed at the signs of the heavens; for the nations are dismayed at them.
Jer 10:3 For the statutes of the peoples are vanity; for it is a tree cut out of the forest, worked with a chisel by the hands of the artizan;
Jer 10:4 they deck it with silver and with gold; they fasten it with nails and with hammers, that it move not.
Jer 10:5 They are as a palm-column of turned work, and they speak not; they are carried, for they cannot go. Be not afraid of them; for they cannot do evil, neither also is it in them to do good.