We have seen new religions spring up very recently. For instance Sikhism. It's essentially a blend of religions, with it's own uniform (the five "K's" ) thrown in to give it an identity. Created 1699 . And Christianity has changed and evolved even in my own lifetime, in the UK, with influxes of African and other people bringing different ideas. The Christian of today would be incomprehensible to the puritan of Cromwell's time.
It's not immoral to eat meat, abort a fetus or love someone of the same sex...I think that about covers it