But Fnord, this is after all, a novel, in which a character called Mackenzie Phillips claims to have met with God. If you are referring to the author, well, many people claim to have met God in one or other form. Just as many folks also claim to have met anyone from aliens, people from the past, the devil, Bigfoot, chupacabras, and other supernatural beings / cryptozoological creatures.
Not all these people had a reason to invent such a tale, as not all of them were looking for money, attention or whatever...
We should view such tales with a pinch of salt maybe, but not discount them altogether, as there are many unsolved mysteries out there...