(BGM from "Worthy is the Lamb")
Nerv, a United Nation special agency, is a secretive organization founded by Gendou years ago to destroy the attacking Angels that come today. They are protected by government's laws and all the things they do are treated as "top secret". Nerv is actually under Seele, the "Human Completion Project Committee". Nerv is actually executing "Human Completion Project", under the inspection of Seele.
Nerv logo
More in-depth info about Nerv can be found below. Be warned that the following info is EXTREMELY SPOILING and is suitable ONLY for those who have watched TV episodes 1-24(at least). If you do not follow I'm sure you will regret what you have done.
Warning! You are now on the way down to Terminal Dogma under Nerv headquarters! Return before it is too late!
You are now near Terminal Dogma! Return now! This is your last warning!
It's already too late...you have come to Terminal Dogma. May God bless you.
Although Nerv seems to be here only for destroying Angels, actually its real aim is to execute "Human Completion Project". From what they found in "Dead Sea Scrolls" and with the use of Adam, they have found/created Rei, EVA-01, and Lillith, which are the most important keys to the success of "Human Completion Project".
("Dead Sea Scrolls" do in fact exist and was discovered in 1947 near the Dead Sea in Israel in an abandoned cave. The contents are the Old Testaments and some parts of the New Testament of both the Jewish Bible and the Christian Bible, written between the 1st and 3rd Century AD, some of the contents of the scrolls remains a secret.)
Actually there is a hidden area called "Terminal Dogma" under Nerv headquarters which is only known by a few Nerv staff, and there resides Lillith. Lillith is the mother of all humans, but how it was found is still unknown. It is a giant entity nailed in a big red cross, with something like "God's Seven Eyes" over its face and its chest penetrated by "Longinus Spear". The Lillith we saw in the TV series was not yet fully developed, with legs still growing. Lillith is actually the FIRST Angel found even before Adam. She is an important key to the success of "Human Completion Project".
(According to Jewish Lore the name of Lillith came from the first wife of Adam. Between Adam and Lillith was born the evil spirits.)
From what Gendou has said, Longinus Spear is a hindrance to the growth of Lillith. It seems that it is used to pierce Lillith to prevent it from growing completely at least until all Angels have been eliminated(but because of emergency, the spear was pulled out to destroy the 15th Angel Arael). Longinus Spear also plays a very important role in "Human Completion Project"(it is used to initiate the Third Impact).
(The spear's name came from the name of a roman soldier who pierced the heart of Christ in the cross to confirm His death.)
Note: Feel free to tell me if you find anything wrong in the above info.
Neon Genesis Evangelion and related images are copyrighted by GAINAX/ Project EVA, TVX, NAS.