I don't believe the Bishop new but Lady Mae did. Mac did all the dirty work for Mae and I would not be superised if she slept with Mac like she did her father even as a grown woman she slept with her dad.
Mac pulled a 2 for 1 scam with that fire...burn down the old church which was a repairs money pit, for the insurance to build Calvary - which I think Bishop was passively aware of. Aaannnd lure Darrell James into the basement to die in said fire so that the estate would go to Bishop, Mae & Mac. The first will gave the estate to Darrell James. The second will gave the estate to the Bishop & Co. after DJ died.