Complex sentence: Orson took Sarah's side and confronted Smith, who denied Sarah's allegation and responded that she was Bennett's lover, causing estrangement between Smith and Orson Pratt, and ultimately resulting in Orson Pratt's discipline and excommunication on August 20,1842.
Split into simpler sentences: Orson took Sarah's side and confronted Smith, who denied Sarah's allegation and responded that she was Bennett's lover. The resulting estrangement between Smith and Orson Pratt, who stood by Sarah in preference to the denials of Joseph, who warned his disciple that, ultimately resulting in Orson's discipline and excommunication on August 20,1842.