Except in terms of hyper-sensitivity, I don't understand Edward's response to your post. However, based on personal reading of antebellum church minutes, he is correct about slaves and white people attending the same church. Membership rolls frequently mention slaves being admitted or dismissed from church.
More to your point, I don't know of any "white" church during pastored by a slave or free person of color antebellum years.
Have been unable to locate any wartime reference to Wimbush or locate him on the 1870 census of any Southern state.
NO evidence that he was actually enrolled in Confederate service.