Free Will vs. Predestination (i.e. A character who knows what is going to happen ahead of time and has the power to change everything, therefore making everything that happens His choice even if only because He allowed it to happen when He could have changed it) is something which requires a degree of just throwing everything to the "I don't understand it but I have faith" bucket of non-thought. While this can fit in a personal philosophy, it doesn't work in literature. It doesn't matter if one of your characters is God, you still have to run the damn story and make it work as a block of prose with an underlying narrative.

Even the Bible's portrayal of God doesn't portray Him very well. It's all over the place, you've got Genesis vs Job vs Ezekiel vs Exodus, then the Christians came and ballsed the whole thing up with the Jesus character. As narrative it's ramshackle and difficult to understand without making lots of jumps and leaps and fitting it into a pre-prepared framework of interpretation. The conclusions of the Catholics or Evangelicals or Lutherans do not, despite what the proponents of those belief systems say, spring unbidden from the text in the same way that the characters of Hamlet or MacBeth do. In order to write a God as consistent and well constructed as Hamlet one would have to discard much of the, well, the richness of the Bible if we're being charitable or the contradictory complexity if we're not, in order to make the character into one that serves a literary purpose rather than one that exists as an object for study in theological colleges.

It's easy to think that God has been "well written" in a story if the character agrees with your own personal conception of God, but this is not necessarily an indication of actual good writing.