I think it'd be great if the military chaplains had the ability to give proper "fire and brimstone" sermons. Maybe some historical Civil War sermons are in the game like in a small book that the chaplain carries.
Another cool thing would be actual Bibles. Many soldiers would carry Bibles on them during the war and you can't exactly have a chaplain without a Bible lol. Also, I think it'd be cool if the Bible was interactive, as in it was actually a KJV and could be read from.