It really depends on how you define a
religious symbol. If by that you mean anything to which any religious significance at all can be attached, then yes, since many Christians have indeed attached religious significance to the Christmas tree (e.g., the Tree of Life, both in Eden and on Calvary). But if, when speaking of a religious symbol for a holiday, you mean a tangible object intrinsically attached to that holiday, and without which the holiday wouldn’t be the same, then no, because the celebration of Christmas does not require Christmas trees.
At root (pardon the pun), Christmas trees are a pretty decoration that Christians incorporated into their celebration of the holiday over the centuries. They have been traced to the tradition of the medieval Paradise tree, decorated with apples and bread; and they have been traced to Martin Luther, who is believed to have brought home a tree to decorate with lights one Christmas after inspired by the starlight filtering through trees during a winter evening walk. They did not become a widespread custom in the English-speaking world until German relatives of the British royal family brought the custom with them from Germany when they married into the royal family in the 18th and 19th centuries. Christians justified the custom on religious grounds by then explaining that in the tree we can see the hope of eternal life. And, even today in many traditionally-Catholic countries, far more emphasis is placed on erecting Nativity scenes – a tradition attributed to
St. Francis of Assisi – than to decorating Christmas trees.
In short, although Christmas trees are a beloved custom in much of the English-speaking world, they are not necessary to the celebration of the holiday and they are not nearly as symbolic of the holiday as the crèche. If you agree that a religious symbol should be understood to mean “a tangible object intrinsically attached to that holiday,” then Christmas trees are a lovely decoration for the season but are not a religious symbol.
