John Milton wrote his Sonnet XIX somewhere in the years 1652-1655. The actual date is uncertain, but given that, overall, his sonnets are numbered in a chronological fashion, this one likely falls in 1655, like Sonnet XVIII. This poem was first published in 1673, in the second edition of Milton's Poems.

This sonnet's principle idea is that God can use all kinds. No matter what your ability, God will find a use for you. Milton illustrates this in the first line, alluding to his blindness (which was, by this time, almost complete). Even through his physical disablities, God has still worked through him.

A . When I consider how my light is spent
B . Ere half my days in this dark world and wide,
B . And that one talent which is death to hide
A . Lodg'd with me useless, though my soul more bent
A . To serve therewith my Maker, and present
B . My true account, lest he returning chide,
B . "Doth God exact day-labour, light denied?"
A . I fondly ask. But Patience, to prevent
C . That murmur, soon replies: "God doth not need
D . Either man's work or his own gifts: who best
E . Bear his mild yoke, they serve him best. His state
C . Is kingly; thousands at his bidding speed
D . And post o'er land and ocean without rest:
E . They also serve who only stand and wait."

Source:
http://www.library.utoronto.ca/utel/rp/poems/milton7.html