What is the relationship between God and man in "The Pulley" by George Herbert?

Herbert is using a pulley as a metaphor for the relationship between God and man. A pulley is a simple mechanical device which you use to lift something up by pulling down on it. God lifts us up by withholding the gift of rest and drawing us closer to Himself. The mechanical metaphor neatly encapsulates the reciprocity of the relationship between man and God.

The central conceit of the poem is God's act of creating human beings. God has a glassful of blessings he wishes to pour into us as he puts us together:

So strength first made a way; 

Then beauty flowed, then wisdom, honour, pleasure.

The most important blessing, the gift of rest, lies at the bottom of the glass. When God has finished bestowing the other blessings upon us, he hesitates. Perhaps it might not be a good idea, God muses, to include this particular blessing in the making of human beings:

“'For if I should,' said he, 

'Bestow this jewel also on my creature, 

He would adore my gifts instead of me, 

And rest in Nature, not the God of Nature; 

So both should losers be.'"

St. Augustine once famously wrote in his Confessions, "Our hearts are restless until they find their rest in thee.” This is what Herbert himself is driving at here. If we were not restless, then we would have no need for God. We would simply spend all our time luxuriating in the myriad worldly gifts that God has so graciously bestowed upon us—without recognizing who was responsible for these gifts in the first place.

It may seem to some as if God is being manipulative here. However, Herbert's answer to this possible criticism is set out beautifully in the last line of the stanza quoted above, "So both should losers be." The implication is that both God and man will be the poorer if our hearts are not filled with a restless desire for the Almighty.

Having been endowed with every possible earthly blessing and joy, it is inevitable that at some point we will grow weary and bored. Under those circumstances, God will still be there for us, whatever our motivations for seeking Him:

Yet let him keep the rest, 

But keep them with repining restlessness; 

Let him be rich and weary, that at least, 

If goodness lead him not, yet weariness 

May toss him to my breast.