'To err is human' - the meaning and origin of this phrase
A proverb expressing the idea that forgiveness is a worthy response to human failings.
Origin
The proverbial phrase 'To err is human' is often heard in its fuller form 'To err is human; to forgive, divine.'. This makes sense of the notion that the originator, the English poet  Alexander Pope, was trying to convey. In the poem An Essay on Criticism, Part II , 1711. Pope explains that, while anyone can make a mistake,  we should  aspire to do as God does, that is, show  mercy  and forgive sinners:
Ah ne'er so dire a Thirst of Glory boast,
Nor in the Critick let the Man be lost!
Good-Nature and Good-Sense must ever join;
To err is Humane; to Forgive, Divine.
Note that Pope's original wording uses the word 'humane' rather than, as it is now usually spelled, 'human'. This wasn't a spelling mistake, nor have we misunderstood the poet's meaning, just that 'humane' was the accepted spelling of 'human' in the early 18th century.