The is not one of telling the truth
The Importance of Being Earnest focuses on the elite, and while making fun of their absurdities and excesses, it also revels in their witty banter and rambunctious lives. Wilde was undoubtedly an astute social critic, but it is his wit that sets him apart.
One of the ways Wilde’s wit manifests itself is in puns. Running throughout the entire play is the double meaning behind the word earnest, which functions both as a male name and as an adjective describing seriousness. The plays twists and turns around this theme, its characters lying in order to be “Ernest,” and then discovering that because of a number of remarkable circumstances they had not in fact been lying at all. In claiming to be Ernest, both Algernon and Ernest had, unbeknownst to themselves, been earnest.
In the figure of Lady Bracknell in particular, The Importance of Being Earnest lightly shows the limitations and unhappiness produced by such a way of life. The play mocks this earnestness; it is the characters who do not act earnestly who are rewarded with love, and who are proven not to have been acting dishonestly at all. With this, The Importance of Being Earnest makes a tentative further claim: that perhaps Algernon, Ernest, Cecily, and Gwendolyn have been the earnest ones all along; unwilling to act earnestly according to social status and convention, willing to lie to get what they want, and never completely able to escape their own delusions, they at least act honestly with themselves. Their earnestness is not one of telling the truth and fitting in, it is an earnestness of going after what they wanted.