This is for all singers, performers, musicians, comedians etc. despite your beliefs, would you perform a piece if the work mentions God, Jesus, religion etc?
I'm Pagan and we have used Gospel music to raise energy in circle before. It's kind of what it's meant to do.
I voted "yes" but I must insert a caveat.
As a performer, playing music is my job. I am about as anti-theist as one can get without being downright militant about it. However, I am also a musician and have been a performing artist off and on for most of my life. I love the art of music, and always have. As a youth I was actually a member of church choir as well as a member of the glee club in junior high school.
There are a number of religious or quasi-religious songs that I have performed in the past. One example would be singing my mother's favorite religious song at her funeral, that being "Joy To The World," with my three sisters (all very religious) in four-part harmony. But that was for Mom, not for me.
There are a couple of others that I have played in the past that I would consider performing today under the right circumstances. One example would be the Doobie Bros. classic hit "Jesus Is Just Alright." I don't care for the message, but I have sung backup on it. It's a well-written piece, and it's a fun song to play on the guitar. I've also played "Spirit In The Sky" by Norman Greenbaum. It's not as much fun to play as the Doobie Bros. song, but it usually goes over well with the crowd and I don't find it horribly offensive.
Playing an instrument for such a song is definitely an easier choice than singing it. I have never performed a particularly religious song vocally in a professional context -- only Joy To The World at Mom's funeral or other songs as a member of church choir in my youth. Banging on the strings is one thing. Singing the words is quite another.
Out of respect for the other artist (the composer) I would not perform any song if I felt compelled to change the lyrics. I would find it disrespectful if someone did it to me, therefore I would not do it to someone else. If I take such offense at the lyrics that I cannot sing them, then I would simply opt out of performing the song rather than changing it.
It really depends on the piece, its' cultural significance, its' musical value, whether I'm saying the lyrics, what the lyrics are actually saying...
For example, I wouldn't mind singing the Beatle's "Let it Be" even though it has Mary embedded in it. Also, I probably wouldn't mind singing Handel's "Messiah" at a public concert, since it is both excellent music and culturally significant.
On the other hand, I had to stop publicly playing drums to worship music during worship services because I couldn't anymore support using music to brainwash beliefs into other people's minds—especially when I have genuinely rejected those beliefs.
I'd have a fair bit of flexibility between these two ends.
I perform as written unless the situation allows for some leeway, which it rarely does.