Complex sentence: Shug influences not only the way that Celie allows Mr. Johnson to treat her, but also her showing Celie that it is all right to commit sin but still believe in and live for God, she broadens Celie's view on religion.
Split into simpler sentences: Shug influences not only the way that Celie allows Mr. Johnson to treat her, but also her religious views. In showing Celie that it is all right to commit sin but still believe in and live for God, she broadens Celie's view on religion.