https://www.whitehouse.gov/about-the-white-house/our-government/the-constitution/
First amendment is freedom of speech and religious institutions are specifically named.
One thing one does not have to do is be around and listen to what they don't want to hear. A Christmas Fair (taking the word Christ out) Xmas. So is it a Christmas Fair or Xmas Fair - is it sponsored by a church -or is it sponsored by Christians. Well if they allow preachers to preach they must be Christians - so don't go to a Christian event if one doesn't want to hear Christian preaching.
For the past 40/50 years Christ is slowly been taken out of Christmas celebrations because people don't want to hear of him, but it's still about the birth of Jesus and has been since it was first established whether mixed with paganism or not.
Heck I don't like rap lyrics and because I don't like rap lyrics I wouldn't go to a rap concert.