In Book 5, before the Fall has yet occurred, Milton portrays morning in Eden, using personification at one point to describe the brilliance of the sun:
So all was cleared, and to the field they haste.
But first from under shady arborous roof,
Soon as they forth were come to open sight
Of day-spring, and the sun, who scarce up risen
With wheels yet hov’ring o’er the ocean brim,
Shot parallel to the earth his dewy ray,
Discovering in wide landscape all the east
Of Paradise and Eden’s happy plains...
This imagery is clearly intended to demonstrate Eden's dazzling beauty: as Adam and Eve exit the "shady arborous roof" under which they have been sleeping, the sun greets them, and though "scarce up risen," its rays illuminate all of Eden, immediately transforming night into day.
Milton personifies the sun as a powerful, omnipotent deity of sorts—capable of enlightening the "wide landscape" of Paradise—and thus draws a clear parallel to God: in this prelapsarian world, whose inhabitants God loves unconditionally (since they have not yet disobeyed him), all Adam and Eve know is magnificence. For now, they are free to enjoy "Eden's happy plains," illuminated by the sunlight of God's favor.
In Book 7, Raphael recounts to Adam and Eve how God created the world, using striking imagery and personification to depict the origins of the natural world, while also foreshadowing Eve's eventual fate:
...Let th’ earth
Put forth the verdant grass, herb yielding seed,
And fruit tree yielding fruit after her kind;
Whose seed is in herself upon the earth.
He scarce had said, when the bare earth, till then
Desert and bare, unsightly, unadorned,
Brought forth the tender grass, whose verdure clad
Her universal face with pleasant green,
Then herbs of every leaf, that sudden flow’red
Op’ning their various colours, and made gay
Her bosom smelling sweet: and these scarce blown
Forth flourished thick the clust’ring vine, forth crept
The swelling gourd, up stood the corny reed
Embattled in her field...
By personifying the natural world as a woman—one who gives birth to nature, and is then clothed by nature—Raphael is drawing attention to the fecundity and beauty of the natural world, God's most impressive creation. Additionally, Raphael creates a parallel with Eve, foreshadowing the ultimate consequences of her disobedience. The natural world is "Desert and bare," "unadorned," or naked—like Eve before the fall—and must be clothed in order to be "made gay." Eve, too, will be clothed by the Son of God (in "skins of beasts") after she eats from the Tree of Knowledge and loses her innocence.
Additionally, Raphael's monologue highlights the central role of women in the world. Eve was created after Adam—from a part of his body—and is implicitly inferior to him. Adam serves God, while Eve serves Adam ("He for God only, she for God in him"). But Eve, the "general mother" of humankind, has the capacity to give birth, just as nature gives birth to more nature: "fruit tree yielding fruit after her kind." (In Book 5, Eve is described as having a "fruitful womb" that will "fill the world more numerous with thy sons/Than with these various fruits the trees of God/Have heaped this table.") As Milton makes clear throughout the poem, this capacity lends Eve a kind of supreme power, justifying her position alongside Adam as representatives of God on Earth.
In Book 9, following Adam's decision to eat the forbidden fruit (because he is "fondly overcome with [Eve's] female charm"), the Earth, Nature, and the sky are personified as individuals in pain or grieving:
Earth trembled from her entrails, as again
In pangs, and Nature gave a second groan;
Sky loured, and muttering thunder, some sad drops
Wept at completing of the mortal sin
Original...
By investing the world around Adam and Eve with human qualities—the capacity to "tremble," "groan," "weep," and experience pain—Milton emphasizes the severity of Adam and Eve's transgressions: humankind has betrayed and damaged nature.
That a planet or an aspect of the natural world could feel pain or experience grief—despite the vastness and power of the Earth and Sky, compared to small, mortal humans—demonstrates the extent to which Adam and Eve's actions are destructive, and the unimaginable repercussions they have for all living things.
Ultimately, this means that humankind will no longer experience harmony with nature, as Adam and Eve previously did in Eden; instead, the natural world will enact revenge on humans (for example, the fact that humans will have to labor hard to sustain themselves through agriculture, and later, the great flood that leads to the building of Noah's Ark).
