So, do you really love the religious aspect of Christmas so much, or do you love hating every possible nuance that you can - however tenuously - attribute to an assault on Christmas/Christianity? It's not even Thanksgiving yet and I'm already seeing posts related to the war. While I wouldn't dare speak for Jesus, I have a hard time believing he'd spend a whole lot of time worrying about what people call a tree during a December holiday co-opted from a pagan religion as a marketing tool.
In my opinion (not that you asked, but if you're not interested, then you can stop reading now), if you want to say Merry Christmas, say it. If someone doesn't say it to you, that's not an assault on your faith. At worst, it's an acknowledgment that not everybody in this country celebrates Christmas and it's presumptuous to assume that everybody does. If you want to call it a Christmas Tree, then call it a Christmas Tree. How does it harm you in even the slightest to have anybody else call it anything else?