The reason I celebrate this holiday is because my secular children do. My son, his wife, their sons. They love to have a beautiful tree, and have a festive dinner. I kept my presents to a minimum, just books for the boys, things I know they would love and use (and they started using them right away). If I refuse to do this much, they would think I was a fanatic, like the "other" grandma, who is Jehovah's Witness. My daughter in law grew up with no Christmas and no birthday celebrations. For many years her own mother will not speak to her or even see her grandchildren, because my DIL is not a Jehovah's Witness now. My presence in their lives is the only Christian presence in the family. I have to do what I have to do.
My house had no tree, no lights, no nothing. I went to church with my neighbors on Christmas eve because I love my neighbors and want to be friendly to them, but I did not like the service, nor the church. It seems very much a "ritual", and what Gerlinda's been showing me about "rituals" has me disliking ALL of them. I didn't realize how bad "rituals" were. I have stopped attending church, at least for now, at least any which have "rituals".

I do not think the tree is any more a symbol of an Egyptian phallus, however.
I think if it means anything to my family it is Tannenbaum, a German tradition which probably was carried out by my daughter in law's Swiss family, before they became Jehovah's Witnesses. And by my English ancestors, who were neighbors of Charles Dickens in Kent. I dislike all things which are ancient Egyptian and all things Babylonian, but I believe "the tree" is no longer that in any sense of the word. It's just a beautiful thing my family loves, nothing like an obelisk or a phallus.
I'm tired, rambling, just putting in a word here for both sides of this controversy. I have learned a lot from all who have posted on this thread.
I am really grateful to Gerlinda for enlightening me about "rituals". I had no idea! I never really liked them, but I didn't know how really bad they are. Wow--old lady learns a new thing!