The speaker begins with a very pessimistic vision of earth that sounds more like the Hell from Milton's epic poem Paradise Lost. The earth is like a huge cavern full of places in which to get lost. He's not exactly full of spiritual hope here.
And that one Talent which is death to hide Lodged with me useless,(lines 3-4)
The speaker gives an example of an "allegorical" reading of scripture. At this time in England, a big debate existed over whether Christians needed the clergy to help them interpret the Bible. Milton and other Puritans held the belief that each individual had the authority to interpret scripture for himself. This viewpoint helps explain the unique reading that the speaker applies to the "Parable of the Talents" in the Gospel of Matthew.
though my Soul more bent To serve therewith my Maker, and present My true account, lest he returning chide; "Doth God exact day-labour, light denied?"(lines 4-7)
The tension between light and darkness is central to the story of Good vs. Evil presented in scripture. Also, the speaker's "Maker" seems more like the harsh and judgmental God of the Old Testament than the loving and forgiving God of the New Testament. Perhaps this is one of the mistakes that patience must correct.
"God doth not need Either man's work or his own gifts; (lines 9-10)
Patience points out what should be an obvious fact: God, the all-powerful, all-knowing Creator of the universe, does not need the extra labor of one guy toiling away down in bonny England. The point of spiritual work is not to increase God's profits; God isn't a Fortune 500 company.
His state Is Kingly. Thousands at his bidding speed And post o'er Land and Ocean without rest:(lines 11-13)
Comparing God to a "King" recalls the parts of the New Testament in the Bible where Jesus Christ is described as "the king of kings." Patience forces the speaker to look at the big picture: God already has people doing "day-labour" to enact His will, so the speaker might need to take on a different role.