There is so much wrong with your post I don't know where to start
I don't need to cite an example of discrimination
You were asked to cite an example and your failure to do so is most likely because your argument is too weak to find support.
Cash call offered it by saying that gay people should be discriminated against in the marriage stakes
Marriage stakes? Cashmcall did not say they should be discriminated against. You are the one who offered that intepretation of what was actually said.
And discriminating against Christians is a totally different thing
Lets see how it might be different: discrimination against Christians is clearly unconstitutional while discrimination against gays is only said to be unconstitutional by a later court ruling that twists the 14th amendment. Both should be avoided but disc against any religious views be they christian, muslim, agnostic or atheist all have the rule of law to condem it.
Gay people are born gay and being gay does no harm to anyone
The scientific evidence about being born gay has always indicated that there is both a genetic aspect and an aspect of environmental influences. The apa has even withdrawn their statement on the issue. The best evidence we have for gays being born that way is that they say they feel like they always have been that way. Christians likewise claim that God elects them so it is God who chooses who will be christian. If you beleive one groups statement then to not be prejudiced you should beleive the other groups.
Christians opt to believe their vicious mythology and seek to impose it on everyone. In fact Christianity is the ultimate in discrimination suggesting that millions of people should be burned for ever for not buying the ludicrous story of god. Christians just think that they have the right to discriminate but not be discriminated against which is totally in synch with their hypocrisy
You understand so little.