MEP refers to Heavenly Parents sending us to earth "to receive further instruction."
Mark E. Petersen, “Be Ye an Exponent of Christ,” in Brigham Young University Speeches of the Year, 1965–1966 (Provo, Utah: Brigham Young University, 1966), 13:53
Think of the type of instruction you received in your pre-existent life as you were taught by your heavenly parents. Infinite people, infinite personages, teaching you likewise to become infinite. And then they sent you here to receive this further instruction.
This part of the speech starts at 13:53.