Complex sentence: Harpo challenges his father to make things right after a bunch of terrible things happen to Mister, which force Mister to try to understand the meaning of Celie's curse and the meaning of life other than his tough childhood.
Split into simpler sentences: Harpo challenges his father to make things right after a bunch of terrible things happen to Mister. Forcing Mister to try to understand the meaning of Celie's curse and the meaning of life other than his tough childhood.