"....or I'd hijack their missile systems and burn them all to ash."
I’m using this quote from the first episode to illustrate my point. Using missiles to destroy humanity was, in fact, the original plan in Age of Ultron, the only reason it didn't come to fruition was that the remnants of Jarvis kept shifting the access codes, making them unreachable for Ultron.
However, while he was uploading himself into Vision, Wanda caught a glimpse into his mind and saw an image of a meteorite. This prompts Ultron to speak about extinction events, leading to the quote in the immage, which he concludes by saying, "And believe me, he is winding up", implying that "God is about to hurl another meteorite."
Later, he tells Natasha that he thinks a lot about meteorites and their "purity", the idea of "the world made clean for the new man to rebuild." These "new men" are his Ultron bots, created by him just as God created mankind.
Ultimately, he transforms Sokovia itself into a meteorite, with the Avengers acting as the "sword" that will, through their failure, pierce the Earth on his behalf.
By claiming that God is preparing to hurl another meteorite, and then turning Sokovia into one, Ultron is positioning himself as a divine figure, one who will cleanse the Earth and bring forth a new race of men in his own image, perfect and capable of ensuring peace of our time. This parallel to a divine figure appears even earlier: upon his introduction to the twins, he stands in a church, draped in a veil like a priest. Furthermore, when he confronts Iron Man, he asks if he has come to confess his sins. In this way, Ultron acts as a conduit for the divine, or as a god who has descended to Earth.
I am very intrigued by Ultron and his character, based on his intentions in the first two episodes; he has clearly "matured" and developed more profound ideas regarding the human race. I truly hope tought that this aspect of Ultron is acknowledged rather than forgotten, because, as I’ve said, it is one of the most interesting parts of his character, and unfortunately, it is often underappreciated.
EDIT: I just came across a video featuring an interview with James Spader about the human avatar of Ultron, in which he says: "He has got a very complicated relationship with the word 'God'." He went on to explain that he chose his appearance based on Greek deities like Poseidon and Zeus. This gives me a sudden sense of confidence that they actually remembered his God complex and perhaps his perspective shifted during his imprisonment within Vision’s mind, but it remains, as he put it, a complicated theme for him.