Complex sentence: Phelps was deeply touched by this development, and upon his return he became an enthusiastic and devoted disciple of Joseph Smith's, who was invited to speak at his funeral following Smith's murder in June 1844.
Split into simpler sentences: Phelps was deeply touched by this development, and upon his return he became an enthusiastic and devoted disciple of Joseph Smith's. He was invited to speak at the funeral following Smith's murder in June 1844.