The story you see in this movie is about regular life with its ugly rearing in occasional violence and cruelty.
What you don't explicitly see, and what this movie is all about, is the hidden dimension, a profoundly spiritual one, that we cannot grasp but, occasionally, we suffer its brutal intervention in the real life that we are well conditioned to perceive.
All throughout the movie there are clues that will explain the seemingly unexplainable actions of the characters. I confess, I was clueless at the end of the movie about almost everything that happened in it. But the revelation came after like a lightning strike that shed light to all dark corners of the enigma.
After all, the movie is, every second of it, about the gargantuan struggle between good and evil. It is about how good and evil is unexpectedly taking shape in the real world. It is about the unbearable burden of sin and the heavy price humans have to pay to redeem themselves from it.