The fountain in its source
No drought of summer fears;
The farther it pursues its course
The nobler it appears.
But shallow cisterns yield
A scanty short supply;
The morning sees them amply filled,
At evening they are dry.
--Madame de la Mothe Guion (1648-1717), translated by William Cowper (1731-1800)
This poem is not "Christian", per se, but Cowper certainly was. His work is featured on both of my blogs. There are links to his amazing life story. Madame Guion was also a fervent Christian, seeking private devotional disciplines.
The poem gives an overall sense of a giving, active life being preferable. The flowing, active fountain which freely gives of itself never has to "worry" about running dry. The still cisterns, from which people come and take what they want, do have that "concern.
Cowper ended up living in the vicinity of Olney, England. There he was friends and a joint hymn-writer with John Newton, author of "Amazing Grace." Though Americans are much more familiar with Newton, Cowper has had more fame in the UK. (As noted elsewhere, Cowper was the favorite poet of author Jane Austen.)
Olney still hosts the Cowper and Newton Museum. On its premises are Cowper's Summer House. After his death, a book was published about the place. "Fans" showed up and wrote on its walls, some of which is still visible today.