Coleridge opens the poem with an address to his fiancee Sara. He muses about their present situation, perched cozily next to one another. Longing for their future life together as man and wife, Coleridge imagines how ideal their new home will be. The image he paints is of nothing but peace and tranquility.
Then, Coleridge introduces the lute or harp. This lute is resting in its case as if tempting someone to play it. This lute is the representation of illusion. While he can imagine what his marriage will be like, Coleridge is limited to his own experience. He won't truly know what the experience will be like until it happens. Thus, the lute is tempting him as if it knew the answers he seeks. Since his mind is upon his wedding to Sara, Coleridge uses an abundance of sensual imagery in describing this lute.
He runs quickly through a lot of nature, thanking God for creating such beauty. He's praising the Creator for giving man such divinely inspired plants and sights and animals to experience and steward. Allowing these ideas to drift along, he concludes that life is contained within all matter, and it is the same life; all things are unified. Life flows through all matter so that all is the same force, which is in fact divine.
Here Sara corrects Coleridge. Quickly he repents from his digression. He apologizes for presuming to place God within all living things. Considering the time period in which this poem was written, these theories are heretical at best. Coleridge, realizing his mistake, gives once more credit to the divine Creator.