I lurk occasionally and know a lot of the regulars give very level-headed advice so I trust you'll give it to me straight...
My FI and I are both agnostic. For me, religion is a very personal topic and I don't discuss my views with many. When we've discussed how to raise our childen, we've both agreed that we'll teach tolerance of other religions/beliefs. When it comes to our ceremony, we'd both heavily prefer a secular ceremony. The problem? FFIL is a former pastor (but still works in that field) and it is very important to FI that his dad performs the ceremony.
I don't have a problem with that but I feel like a fraud. FMIL/FFIL don't know our views. I feel it is disrespectful to ask him to perform our ceremony but leave out all aspects of religion. He seems to be very tolerant of other religions (specifically trying to incorporate Jewish traditions in another ceremony he performed for a mixed-religion couple) but I think that's completely different than saying "please don't mention God."
We meet tomorrow to discuss the ceremony. He'll know then that we are using all secular music and a non-religion reading (my niece, from a children's book), but am I not being honest with him? Should we disclose our beliefs? I don't feel entirely like I am compromising my beliefs... it's more important to me that my FI has his dad perform the ceremony, no matter his beliefs. Make sense? My FI is hesitant because to him, there's nothing wrong with it, so why rock the boat.