TexasWSP, I get what you're trying to do with the joke. However, that type of joke is contextual. A white man making that joke out of the thin air isn't funny 95% of the time and I don't think you cracked the 5%.
You could've made the same point by saying he is some people's Messiah or Jesus, without saying "Black Jesus." Then you would've just offended fellow Christians.
And please believe that I still don't find the humor in "Barack the Magic Negro."