When I heard Rescue sing this song, it took me back to the Africa I knew in the 1950s through the 70s. The emphasis is on the excellance of the voices and the message, which is NOT in modern Contemporary Christian Music. CCM is all about loud instruments and vain repetition-- gotta get the rush.
Rescue is forced to have very disciplined voice control because they cannot fall back on electronically correct instruments. At times one can hear what is called "the fifth sound" found almost exclusively in barber shop singing. This fifth sound is made when all voices blend so well that is creates an external sound more sweet than the individual voices of the singers.
The following video has no photo of the singers. You can find plenty at Google video search with the words "acapella rescue brazil". You will notice that the group is mixed race. I suspect the African roots of the Black Americans is significant. But, why are all bass singers tall and skinny?
Also, Rescue is wildly popular in Brazil. I think they distilled the African and the Brazillian sound. Some of their songs are too over the edge for me, but this one is very interesting. I hope my African (the original Wogs) enjoy this one: