John Donne - Mercurius Gallo-Belgicus

Like Esop's fellow-slaves, O Mercury,
Which could do all things, thy faith is ; and I
Like Esop's self, which nothing. I confess
I should have had more faith, if thou hadst less.
Thy credit lost thy credit. 'Tis sin to do,
In this case, as thou wouldst be done unto,
To believe all. Change thy name ; thou art like
Mercury in stealing, but liest like a Greek.

John Donne

http://www.poemhunter.com/poem/mercurius-gallo-belgicus/