In a sense this is the easiest question to answer, but also the hardest. Easy insofar as the Bible says that we should worship God alone and through Jesus only. Therefore making sacrifices to the ancestors or being obedient to them constitutes syncretism. But it is hard because for many African people the belief is that if the ancestors are not kept informed as to events in the lives of their children they may become angry and withhold blessing or send misfortune. This is so far from my western Christian worldview that I struggle to engage with it - but I know for some, this is part of their upbringing and they see no reason for it not to be true.
It would be good if there were black Africans who could engage with me on this . . .
So next question - how do we turn the theological blogosphere less white?
How do we get black Africans to trust white Africans with their theological thoughts?