Well, Adam is the first Angel. Lilith (eve) is the second. Both of these angels were named after the first people on earth, according to Christianity. Lilith created all life as we know it, collectively referred to as Lilin. Adam created all of the Angels. One possesses the Fruit of Knowledge (brain), while the other possesses the Fruit of Life (the S2 engine, which grants unlimited power and regeneration). In the Evangelion series, both sides, the Angels and the Lilin, fight for Earth. Only one will win; If the Angels get to either Adam or Lilith, all life as we know it on earth will be completely eradicated. The angels will reign.
I just realized something. I have no life.