Why Did George MacDonald "turn with loathing from the god of Jonathan Edwards"? Ron Dart

In an interview between John Piper and Tim Keller, Piper quotes George MacDonald as saying, "I turn with loathing from the god of Jonathan Edwards." This leads Keller to question whether MacDonald was a Christian. Why would MacDonald say such a thing of this American hero of the Great Awakening? What was it about Edwards' Calvinist God that caused MacDonald to react to strongly? Ron Dart examines MacDonald's Calvinist roots and his connection with the Anglican scholar, F.D. Maurice, who played a role in liberating MacDonald to a new way of seeing God.