"So the slaves displayed the images of the saints but addressed them in the parallel names of their own deities - St. Lazarus/Sopona, St. Anthony/Ogun, Our Lady of the Candles/Osun, etc. and here is the point: this never constituted a spiritual dilemma since the system of the gods has always been one of complimentarities, of affinities, and of expansion - but of the non-aggressive kind. the deities could subsume themselves within these alien personages and eventually take them over.
one cinematic illustration of this suggests itself - those films of alien body snatchers where the creatures from outer space insert their beings into the carapace of earthlings, eventually dominate, not only the human forms but the environment and culture, insert themselves into crevices of landscape and social actualities, and can only be flushed out with the aid of weed killers, flame throwers, gamma rays or quicklime. the difference, of course, is that the African deities were made of sterner yet more malleable stuff - the principle of alloys. always generous in encounters with alien “earthlings”, they accommodated, blended, and eventually triumphed.”
-Wole Soyinka from his essay in Orisa Devotion as World Religion: The Globalization of Yoruba Religious Culture ed. by Jacob K. Olupona and Terry Rey