Strange message sent to me

This is part of a letter sent to me through the mail. It had no return addy. I believe it is gnostic in nature, but have never seen anything likke it before. Any one familiar with gnostic writings recognize it?

When all the seed shall have come to perfection, they state that then their mother Achamoth shall pass from the intermediate place, and enter in within the Pleroma, and shall receive as her spouse the Saviour, who sprang from all the Æons, that thus a conjunction may be formed between the Saviour and Sophia, that is, Achamoth. These, then, are the bridegroom and bride, while the nuptial chamber is the full extent of the Pleroma. The spiritual seed, again, being divested of their animal souls, and becoming intelligent spirits, shall in an irresistible and invisible manner enter in within the Pleroma, and be bestowed as brides on those angels who wait upon the Saviour.
The Demiurge himself will pass into the place of his mother Sophia; that is, the intermediate habitation. In this intermediate place, also, shall the souls of the righteous repose; but nothing of an animal nature shall find admittance to the Pleroma. When these things have taken place as described, then shall that fire which lies hidden in the world blaze forth and burn; and while destroying all matter, shall also be extinguished along with it, and have no further existence. They affirm that the Demiurge was acquainted with none of these things before the advent of the Saviour.
Those souls which possess the seed of Achamoth are superior to the rest, and are more dearly loved by the Demiurge than others.
The Demiurge, while ignorant of those things which were higher than himself, was indeed excited by the announcements made [through the prophets], but treated them with contempt, attributing them sometimes to one cause and sometimes to another; either to the prophetic spirit (which itself possesses the power of self-excitement), or to [mere unassisted] man, or that it was simply a crafty device of the lower [and baser order of men]. He remained thus ignorant until the appearing of the Lord. But they relate that when the Saviour came, the Demiurge learned all things from Him, and gladly with all, his power joined himself to Him.

This is something Gnostic, I've heard these terms used before in this context, I'm too tired to decode it but we have a lot of Gnostics on this forum and that might be helpful.

it's from the Adversus haereses by St. Irenaeus of Lyons.

It's not Gnostic, it is anti-Gnostic.

Wikipedia link about the Adversus haereses

And the source of the bit you quoted Book I, Chapter 7

Hope that helps

What the heck, I'll take a stab at it.

Tell me if this doesn't explain everything:

en.wikipedia.org...