We are now more than halfway done showing Evangelion, and many questions still remain. What are the Angels? Why are they attacking? What exactly is the purpose of Nerv? Are they there to protect mankind from the Angels, or are they up to something else entirely? What is the Instrumentality of Man project?
While many things transpire in Evangelion, and while a multitude of themes and concepts break through the surface at times, the common theme, the thread from which the entire story is spun, remains illusive.
The opening sequence provides the first key to the mystery. Within the very first few seconds, a diagram formally known as "Systema Sephiroticum" ("The Sephirothic System") flashes on the screen. The premise behind the drawing is deeply woven into religion and mysticism. Depending upon to whom you talk, the drawing itself has two different meanings. Philosophers regard it as a diagram that outlines the thirty-two paths to wisdom. Others see it as the framework, the model, through which God created mankind and the universe. Occultists claim its origins to be a collection of secret knowledge, handed down directly from God, which provides man with the ability to approach God directly. In the very least, it appears to be the driving inspiration behind Nerv's creation of the Eva units and all of their other related projects.
The Sephirothic System is just one piece of the puzzle; the Angels themselves are also mysteries. Are they acting on behalf of God to destroy mankind for their attempt to follow the Sephirothic System (therefore elevating themselves to god status)? Or is Nerv even going so far as to become gods themselves, by creating life with the Instrumentality of Man project and thus inviting the wrath of God via "angels"? The title of the project alone implies that man can be artificially created and that it is within Nerv's power to do so. In the Bible, God struck down the tower of Babel because the tower was being built by man so that man might reach equal footing with God. Finally, at the end of episode 15, we see Terminal Dogma. Here, deep within Nerv headquarters, is Adam: "The start of everything." On Adam's face are the seven eyes of God. This is yet another symbol that strongly implies a connection between God and the Angels.
Many things in Evangelion also appear to be similar to occurrences in the chapter of Revelation in the Bible. The fire and brimstone of the Second Impact, the resulting floods that killed more than half of the world's population, and the constant attack of the Angels all mirror Armageddon. Nerv's science itself (implied in the Instrumentality of Man project) could be interpreted to be the "false prophet" that leads man away from God. After all, if mankind attained the ability to create life, then what role would there be left for God to fill?
In episode 14, Nerv mentions that everything (the invasion of the Angels, for example) is going according to the Dead Sea Scrolls. The depth of Nerv's involvement in the grand scheme of things is partially revealed. Whether or not they can create life, whether or not they have any control of the Angels, it is clear that they are using the invasion of the Angels in "the plan." It would appear that Nerv is using the Angels as stressors, with Eva as a tool, to force mankind (a.k.a. Shinji) to evolve. This would certainly be keeping in spirit with the Sephirothic doctrine that Nerv follows.
Not all of Evangelion's themes center around Nerv. The main characters, Shinji and Rei, play critical roles as well. They allow the series to also explore the nature of humanity and what it means to be human. Shinji's persona gives way to a pseudo coming-of-age story as he struggles to understand himself and to come to terms with his father. With Rei's character, Evangelion explores philosophical ground as she struggles with the meaning of humanity and even the nature of her own existence. In episode 14, she remarks:
Made from red soil is a human.
What is the nature of evolution? Does it occur in small steps or in sudden cataclysmic events like the Second Impact? What is man's relationship with God, or does "God" even exist? Evangelion raises many questions. Much more than anyone can answer. But one thing is for certain: The creators of Evangelion [Gainax] leave no stone unturned in their pursuit of excellence.