Why sit ye idly dreaming all the day,
While the golden, precious hours flit away?
See you not the day is waning, waning fast?
That the morn's already vanished in the past?

When the glowing noon approaches, we will rest
Who have worked through all the morning; but at best,
If you work with zeal and ardor till the night,
You can only make the wasted moments right.

Think you life was made for dreaming, nothing more,
When God's work lies all unfinished at your door?
Souls to save and hearts to strengthen-ah! such work,
Such a richly freighted labor, who would shirk?

Then arise, O idle dreamer! Dreams are sweet,
But better flowers are growing at your feet.
If you crush, or pass unheeding, idle friend,
You shall answer for their ruin in the end.

Ella Wheeler Wilcox

http://www.poemhunter.com/poem/arise-17/