Against the "striving" grain

My friend was reflecting on the phrase "lest too light winning make the prize light" from The Tempest; how people tend to treasure things more if they worked hard to get them.

It came upon me how irrational this might sound when it comes to our relationship with God. We cannot "earn" our salvation through the things we do, for He loves us regardless of what we do. In fact, it's the opposite, He worked for us by sending Jesus to save us even though we did not earn it. He gave it freely to us. Although this might support the phrase's rationale to a certain extent as God "worked hard" for it, but to Him, the prize wasn't "light" to begin with. He values and cherish us all the same.

Unless the LORD builds the house, 

its builders labor in vain.
Unless the LORD watches over the city,
the watchmen stand guard in vain.

In vain you rise early

and stay up late,

toiling for food to eat—
for he grants sleep to those he loves. 

(Psalm 127:1-2)

Conclusion? I believe the amount of hard work put in reveals that you do not in the first place think the prize is light, but treasure it, that's why you want to strive for it, i.e. you reveal how much you treasure something by the amount of work you put in. Seems like a chicken and egg issue again.

On a side note, would you call this too "easy" for us? Then in this case do we take God for granted?