Once upon a time, there was the Monad.
The Monad was the utmost God; the higher being beyond the clouds
One day, he decided to create an offspring and he created a family of smaller Gods.
Among those newly formed Gods was Sophia.
Sophia was curious, so in her naivety, she decided to create a smaller God of her own.
This was to be called the Demiurge.
The Demiurge was the "grandson" of the Monad and since they were so far removed, the Demiurge had but a hundreth of the power that his "grandfather" had.
The Monad wanted to create the material world but he felt like he wasn't quite done with planning yet.
The Demiurge, given his lower insight into how things worked, decided to create the material world himself, behind the Monad's back.
Due to the Demiurge's lack of knowledge, he accidentally created a hellish world full of pain and cataclysms.
This has made a lot of people very angry and been widely regarded as a bad move.