By Gabe LaMonica, CNN

(CNN) -A tree lies at the root of discord this holiday season.

During the National Christmas Tree Lighting, President Barack Obama spoke in no uncertain terms about the Christian nature of the holiday season, and he didn't hesitate to use the word Christmas.

“It’s a shame that the president totally dismissed the other adherents, the other celebrations that are happening at this time," said David Silverman, president of the American Atheists.

“It certainly isn’t rooted in Christianity,” Silverman said about the National Christmas tree.

He pointed to a passage from the Bible, Jeremiah 10:2, “Thus saith the Lord, Learn not the way of the heathen … for they cutteth a tree out of the forest … They deck it with silver and with gold; they fasten it with nails and with hammers, that it move not.”

“Christmas trees predate Christianity," Silverman said, "and Christianity came along and said, ‘All right, well, we want to spread our message, so, OK, now they’re called Christmas trees, and you don’t have to change your celebration.’

"But the entire concept of trading gifts, of decking an evergreen tree with tinsel of silver and gold and singing songs and roasting chestnuts on an open fire, that’s all taken, 100% of it. The only mention you’ll find of Christmas trees in the Bible is when God says not to do it.”

Bill Donohue, president of the Catholic League, could not disagree more. “I commend (Obama) for speaking honestly and plainly. ... Others should follow suit,” Donohue said.

In 1832, Harvard professor Charles Follen introduced to America the four centuries-old German custom of bringing an evergreen tree into the home and decorating it to celebrate Christmas.

This holiday season, the Christmas tree tradition has stirred controversy in at least two state capitals.

Until it was renamed a holiday tree in the mid-1980s, the evergreen that stands at the Wisconsin Capitol rotunda every December was called a Christmas tree for 70 years.

This year they are calling it a Christmas tree again.

Conversely, the tree in the Capitol rotunda in Providence, Rhode Island, will be called a holiday tree, for the first time this year.

“Standing by itself, it doesn’t make any sense,” Donohue said, “I would agree with that, if that were the only issue on the table, then who would really care? But what I look at is a pattern, and it’s not just Christmas trees being called holiday trees.”

The Catholic League president blames what he sees as a " kind of militant secularism, this dogmatic idea that we can’t have any semblance of religion in the public square without somebody attempting to at least pare it back, if not ban it all together.”

But Silverman said this time of year is for all people, not just Christians: “Christianity thinks it owns this whole season, but this season, it belongs to everybody, and Christianity is not the first, nor the 10th religion to try and usurp the winter solstice for their own.”

Looking out his window across the street from the Catholic League offices in Manhattan, Donohue sees a huge word on a decoration hanging by Macy’s. “It’s very nicely done, with the crafting of the script and the colors, and it says, ‘Believe.’ But belief has to have an object,” he said.

He added, “We’re so afraid of offending people, yet we don’t mind offending most Christians when we tell the kids, ‘Be careful what songs you sing at the, quote ‘Holiday concert.’ ”

“Multiculturalism,” a term that Donohue said embodies relativism, “in its most benign expression would be that we should come to appreciate other cultures and not just have one standard upon which we judge the rest of the world. But in its more typical application, it has basically meant a disdain for Western civilization.”

Silverman counters, “The reason that you are getting fervency from the other side, the religious right, is because they know we’re winning.

“They know that, 10 to 15 years ago, nobody was saying Happy Holidays, everybody was saying Merry Christmas, it was all about Jesus, and they’re losing, and they’re not losing because of violence, they are losing because people are simply realizing, en masse, that religion is full of crap. And you can quote me on that,” said the president of American Atheists.

Despite the two men's disagreements, Obama seemed to suggest at the tree lighting that the celebration brings differing sides together.

“No matter who we are, or where we come from or how we worship,” the president said about the birth of Christ, “it’s a message that can unite all of us on this holiday season.”

But united or not, winter is coming.