Christmas tree is just a fragment of a past religion

Oh yeah, good ol' Saturnalia. Gift giving was also a big part of it. As was the lifting of social divides. Some traditions endure better than others, of course.

Without a doubt that's where the evergreens portion comes from. That's the problem when you make only one religion legal and enforce it . People don't give up their traditions and beliefs just because someone comes along and says it's now illegal. Then add in your enforcers are generally from the same people you can either kill large portions of your population (they did that too) or just give in and make it acceptable. Shoot half the Roman Catholic saints wouldn't have even recognized the church as an authority. But hey it's tradition. Tradition!!!