"Even" a song such as "Kumbayah" sung with a group's whole heart and soul can raise spiritual energy."

I agree Azizi. But that song takes a damn lot of spiritual energy to raise up any enthusiasm for it for me. ;-)

Besides, there are, IMNSHO, much better spirituals than "Kumbayah" or "We'll Overcome". Songs like "Ain't Gonna Let Nobody Turn Me Around" or "Wade in the Water" or "The Gospel Train" or even "Swing Low Sweet Chariot" when done in the traditional call and response chant style (again, my personal favorite style of gospel, along with shape note) are more powerful for me. But it's all a matter of taste, isn't it? I know what you mean about "Kumbayah". I feel the same way about "Danny Boy" which most folkies hate, for the same reason they hate "Kumbayah". But both are songs that in their time and in the context of the communities that gave birth to them, were sung very reverentially and had deep communal meaning. We've just lost that context today.