It is easy enough to be prudent
When nothing tempts you to stray,
When without or within no voice of sin
Is luring your soul away;
But it’s only a negative virtue
Until it is tried by fire,
And the life that is worth the honour on earth
Is the one that resists desire.

Ella Wheeler Wilcox (1850-1919) American author, poet, temperance advocate, spiritualist

Poem (1892), “Worth While,” st. 2, An Erring Woman’s Love
    (Source)

Sometimes called "The Man Worth While." Collected again in Poems of Cheer (1910).