If the stated purpose of a voluntary enterprise is to exemplify a particular ideal or practice and you decide to be a part of said enterprise, that means you are signing on with and agreeing to those stated purposes.
So you think church groups ought to be able to discriminate by sexual orientation in employment?
If one of those purposes is to show diversity by having a diverse board and your addition would skew the stated purpose away from its goal, how are you being discriminated against?
If one of the purposes of the First Church of Sexual Purity is that it contains an all-heterosexual, Christian, White workforce, should a non-heterosexual, non-Christian, or non-White person feel they've been discriminated against?
You would read the mission statement and/or talk to the founding members of the group before applying, would you not? you would do your due diligence, correct?
I'm not sure what you're asking. I wouldn't want to belong to a board that had 'diversity' as a goal, if that goal was advanced by discrimination by race.
I would ask why they think diversity is more important than not discriminating by race, since discriminating by race has been a proven moral evil. I'd ask why they think diversity of superficial and irrelevant characteristics to performance, like race and gender, are given service, but diversity of opinion (the thing that really counts, I'd say) is tossed aside. I'd ask why not diversity in height? Surely the very short and the very tall have a far different life experience to the average heighted.
I know I'm in the minority. For example, I'm grown up enough that I
don't lose my mind if my GP doesn't 'match' my race and gender.
I've even filled scripts from GPs who have black skin and GPs who have vaginas. I didn't even
ask to see a white male GP, that's how strong I was.