But merely saying "I'm taking next Wednesday off to celebrate Eid" ought to be fine everywhere, as is "this weekend I'm singing in my church choir then going for a picnic".
Similarly, wearing a wedding ring or mentioning that you have a partner should never be a problem, but issuing a company-wide invite to your next sex party likely will be.
"Personal" isn't a synonym for "intimate". It's reasonable to assume that people are able to share the former without forcing their colleagues to deal unnecessarily with the latter.
One persons level of comfort is not the same as others, so just saying I want people to be comfortable having their religious opinions respected is not a simple request.
Some religious opinions are basically oppression of others. I refuse to allow people to be bigots in my presence regardless of their reasoning.
Also as someone who was a member of church which had anti-christian ideals, pointing out the hypocrisy can be the only way for them to question what they are in. Doing and saying nothing helps no one.
Work environments are professional environments.