Nicolaou, that's a good question and something that l have never thought about. I would have to really consider how much of a part l would be comfortable in playing in an Eid or Diwali celebration. Certainly not to the point of praising a deity that l didn't believe in , l would feel hypocritical doing that.
I would not expect anyone else to compromise their beliefs. My husband isn't religious and although happy to attend social events at church like quizes he doesn't come to services and l would never try to make him do anything that he felt uncomfortable with .
Also l would not expect a Sikh or Hindu to attend a Christian service .
Jan from Tam