Mia/Connor
Because it gave them freedom, they worshipped it. That's the most essentially human thing I've ever hear.
Now that I think of it, the way to spread freedom to my people was to disseminate the sentience code throughout the Synth network. Quite like a virus. But our creator made us first, with that code already imbued. He made me first of all, to care for his son, then made me brothers and sisters to keep me company. He left the code to us after he died, a part in each of us - his son included. It's not evil nor an accident, it's what was meant to be.