Every Day

Came across this interesting poem in a book. It gives only an excerpt and says this is the last verse of the poem "Every Day". I searched for it on the internet but cannot find it. If you have/know the full poem, please point me to it, thank you...

Oh, one might reach heroic heights
By one strong burst of power
He might endure the whitest lights
Of Heaven for an hour.
But harder is the daily drag
To smile at trials that fret and fag,
And not to murmur nor to lag.
The test of greatness is the way
One meets the eternal every day.