What is a summary of "Air and Angels"?

In the first stanza, the speaker discusses how he first experienced romantic love in abstract form, as a desire for love. However, a desire for love could not, by itself, satisfy him. The speaker needed an object for his love—in other words, a real person to love. He therefore asks Love to send him a physical woman to love. This is a reversal of how love is usually described. Typically, it is understood that a person sees another person who is desirable, and then love follows, not vice versa.
In the second stanza, the speaker discovers, however, that he was wrong to think he would find love primarily in the physical attributes of the beloved. He discovers that love can reside neither in pure abstraction ("nothing") nor in the purely physical ("things"):

For, nor in nothing, nor in things
Extreme, and scatt'ring bright, can love inhere . . .

In the real world, pure, abstract love ("air") is impossible, and a perfectly pure love (the lover as "angel") is impossible, too, so human love resides in some place between:


As is 'twixt air and angels' purity,
'Twixt women's love, and men's, will ever be.

John Donne’s “Air and Angels” is a poem about love. The speaker addresses the poem to his beloved, pondering the nature of love as a pure emotion in comparison to its embodied form in a person. He provides an analogy between the shapelessness of the apparition of angels and the essence of the quality of love. In initially approaching his beloved, he cannot see anything concrete: “Some lovely glorious nothing I did see.” This nothingness is insufficient for human beings; however, we must have a physical form in which to contain our love:

But since my soul, …
Takes limbs of flesh, and else could nothing do….
Love must not be, but take a body too….

The speaker then addresses Love (personified), asking that it take physical form in the beloved as well, “fix itself in thy lip, eye, and brow.” Reflecting on how love is thus manifested, he has to conclude that manifestation through bodily attributes is too difficult, and he must resign himself to the immaterial nature of love, comparing it to air: the angel’s face and wings are “of air, not pure as it.…” The love between the two of them will be like the difference between air and purity:

Just such disparity
As is 'twixt air and angels' purity,
'Twixt women's love, and men's, will ever be.
https://www.poetryfoundation.org/poems/44091/air-and-angels-56d2230aa341c