My family and I visited a black church in Atlanta a few years ago (we were the only white people in the building). The message was inspiring and the members treated us like family. Very enjoyable.
My first church experience ever was at a black Holiness church in Athens,Georgia in 1972 and my reception was identical to yours.
However,many of the congregants were very much alienated and angry at the larger white society.
Was that a healthy attitude?Probably not.Was it justified?Well,after listening to many of the life histories of these mostly elderly blacks,I can sort of understand how they might feel as they did.