The "Xmas" tree is actually an old European pagan symbol and nothing to do with the Jewish boy who made good two thousand years ago and who lived in a place that was kind of short on fir trees to start with. It's evergreen, a promise that the sun will return and the world will be green again and we won't starve in an endless freezing dark. It's the same with holly boughs and wreathes, a promise of green to come.