Here’s what I wrote back:
Nobody is taking away your right to say Merry Christmas.
Say it all you want. Say it to everybody you meet. Say it for your own reasons, shout it from the rooftops that you are a Christian and wish the whole world were Christian.
And I hope people say Merry Christmas back to you, just as I know you will say Happy Hanukkah back to Jews and Happy Divali back to Hindus when their holidays come around.
Nobody in America has the right to take away from people their freedom to express their religious feelings and beliefs.
It's not your fault that historically Christians did so much damage to others in the name of Christ, and so many people today, when they see a cross around somebody's neck, remember those awful times, and fear their return.
It's not your fault that so many people who identify themselves as Christians today insist their religion (not just their religion, but their particular understanding of it) should dominate all others in America, as they did in California recently when they bullied others with the view that the Bible should trump the Constitution and that non-Christians should be required to follow Christian rules – and that they have inspired an all-or-nothing political correctness backlash which supports the view that maybe it's better if all expression of religion is restricted in public places in order to avoid possible conflict.
I'm with you. I think Hindus and Muslims and Zoroastrians should be encouraged to be chaplains in the army, and say the opening prayers in Congress and at presidential inaugurations. I think that Jews should be able to stand up in State Legislatures and other public places and say Christ is not the Messiah, and people should listen with polite attention, even when they do not agree. I think Mormons should be able to insist publicly that Christians who believe Jesus was God are wrong, that God lived in human form on a planet near the star Kolob, had carnal sex with Mary and produced Jesus and his brother Satan. I think they should be able to say prayers reflecting that view in the public schools, and say publicly that portions of the Bible are wrong because they were mistranslated by corrupt catholic priests, and those who do not agree with them should pray quietly in their own way.
Then, when all the religious bullying has stopped, and we are all free to be fully religious, or fully non-religious, each in our own way, there will no longer be any objection to public displays of "Merry Christmas." Then we will have complete religious freedom at long last in this country, and not just freedom of religion for those who outnumber the rest.
Meanwhile, don't be too hard on those well-intentioned folk who believe we should keep our religious expression to ourselves. They are sincere and practical people and they are working as hard as they can to assure we don't return to those days when we routinely tortured and killed people who did not worship God in our way. Their advice for everybody to stay cool is not the worst advice we could take.
Merry Christmas to you. And Merry Christmas to your Christian friends.