User blog comment:Master Plaga/If you think about it, Humanity is the Third Angel/@comment-3517267-20140115160732

The main problem with the version of Neon Genesis Evangelion we got is the fact that a lot of backstory is left unexplained. This backstory would have been a lot more explained in the plot of the Proposal.

That being said, one of the possible explanations for the Angels "birth" (beside Kaworu, since he has been created by the humans) is the fact that only their bodies were created before Lilith came to Earth. Adam didn't have the time to finish its work and was neutralized by its Spear of Longinus. Lilith did its own stuff, giving birth to Lilins (both bodies and souls). When Adam was reawaken during the Contact Experiment, it finished its work by opening the Doors of Guf during the Second Impact and gave souls to the dormant Angels' bodies, hence why we saw them only after the Second Impact.

This way, we still have the humans as the final Angel. Although, technically, you're right when you say they are the first active Angel, beside the two Seeds of Life.