If a thing is worth doing it is worth doing well.
如果事情值得做，那就做好。
If it is worth doing, then it is worth doing well, otherwise it is just a waste of time and energy.
If you decide to do it, please try your best, otherwise the result may be not as satisfactory as you previously expected.
Then you may complain about the unfairness of the God: I have paid so much on the job and why I was rewarded so few.
Actually, what we have obtained may be always match what we have paid.
The reason for our complainments may be only for one thing: We did something wrong previouly.
I can‘t change the direction of the wind, but I can adjust my sails to always reach my destination.
我无法改变风向，但我可以不断调节船帆来让我最终到达目的地。
There are too many things in life that are out of our control.
The only thing we can do may be to alwasy adjust oursleves.
Remember we may change the adverse into favourable things.