Origin of Evil
When Hashem created the world, He placed Adam and Chava in Gan Eden (The Garden of Eden), where Good and Evil were distinct, and it was clear that Hashem was at the Origin of everything.
After Adam and Chava ate from the Tree of Knowledge, the whole dimension of Eden collapsed, and Good and Evil intermingled. From the debris of this collapse, our world was created.
Our task is to discern between good and evil, to choose good, thereby separating the holy sparks from the evil ones and elevating them on High. Concretely, we accomplish this by confronting the challenges we face ethically and according to Torah guidelines.