Complex sentence: He was sustained to the Twelve on October 4,1986, and ordained an apostle on October 9,1986 by Thomas S. Monson, following the death of church president Spencer W. Kimball.
Split into simpler sentences: He was sustained to the Twelve on October 4,1986, and ordained an apostle on October 9,1986, by Thomas S. Monson. He became an apostle following the death of church president Spencer W. Kimball.