The theme of Wordworth's poem "Lines Written a Few Miles Above Tintern Abbey, On Revisiting the Banks of the Wye During a Tour" is that of the power of nature.
Perched above the actual abbey, Wordsworth is able to look down a get a larger picture of what is surrounding him. This being said, Wordsworth admits to the fact that this is the place where he can always find comfort.
The title of the poem provides a perfect name. Wordsworth is looking down upon nature's glory. In doing so, Wordsworth is able to find comfort in the things he remembers because of the abbey.
Wordsworth knows that the power of nature is great- it can take away the pains one feels in life.
Wordsworth is not alone, nature surrounds him:
For thou art with me, here, upon the banks
Of this fair river; thou, my dearest Friend