With all your might
Whatever your hand findth to do, do it with all your might.
Put your whole heart into each task.
Do not do anything half heartedly.
Neither God nor man is pleased by work done for them, by another, in a half hearted fashion.
God looks at the heart.
A zealous heart in an unbeliever, is more pleasing to god, then the half hearted effort of a believer.
This is what is meant by the saying, I wish you were hot or cold.
But because you are lukewarm, I will spew you out of My Mouth.