We're approaching the end of Gates of Paradise. After the end of a life there's a beginning. Here we have generation; birth and death are simultaneous. We see Mother Earth with the worm, symbol of mortality (and of many other things as well).
"16. Thou'rt my Mother, from the womb;
Wife, Sister, Daughter, to the tomb;
Weaving to dreams the Sexual strife,
And weeping over the Web of Life."
To understand this picture we need some familiarity with Blake's use of sex in his myths. It goes back to the earliest literature of our culture, when the sky God was dominant and active while the Earth (Mother) God is passive, receptive, the yin to God's yang.
Digby, page 50: "The realm of the female goddess, the dark, conditioned, Yin side of life, is by itself a place of weeping, of strife, of illusion. It has to be redeemed by its opposite, the contrary state, the light, formative, Apollonian, or Yang side. The ignorant man [the sinner] wanders away into the realm of the Mother, and the farther he goes the more hopeless his lot becomes."
In the Bible such a man was Achan, described in Josahua 7. He had stolen plunder from a battle of Joshua's army for Canaan, the spoils of war, supposed to be belong to God; as a consequence Achan suffered a terrible fate. Blake created a terrible image for this state in Jerusalem plate 25 (Erdman 170-1)
The Valley of Achor became a symbol of failure, of sin, suffering, like a nest of robbers, expressed by the "terrible image" of Plate 25. But we learn from Hosea that there was redemption. Chapter Two portrays the reality of the valley of Achor, but shows a redemptive outlook (beginning with verse 13). Blake was very familiar with the Valley of Achor as it's described in Joshua and in Hosea. In it the ignorant man, the fallen woman suffers, but receives forgiveness and becomes a "door of hope".
This little picture, created by Blake in 1794, was elaborated in the next 20 years into thousands of lines of poetry about female love and eventual redemption.