I'm sorry, but the idea of a fir tree in the house on winter solstice is taken from Nordic legends as is the yule tide log
There's nothing to be sorry for. It might very well be a Nordic legend but I don't believe the Christian use and symbolism of the tree has it's roots there. Even if it would, so what? To me the Christmas tree is a symbol of Christ being the Light of the world and, also, a symbol of the Trinity. If someone is offended by that, too bad. If we continue to minimize Christ at Christmas we should not at all be surprised if Satan steps into the vacuum that has been created. He always does...
Just because one group uses something to symbolize one thing doesn't mean another group can't use the same thing to symbolize something else.