The Importance of Being Earnest and...
"Being Earnest" and "Being Ernest" are two contradicting actions in this story because of deception. When Jack is Ernest, he is lying about his identity and creating a false persona, but being earnest means being honest and true. In the case of Jack, it is important which "earnest" he is. He has to be true to the love of his life, even though she has only known his false persona, Ernest. He has to be earnest to her to keep her happy and prove his worth. But, considering she wants to only marry a man named Ernest, he has to lie about his identity to marry her. His original deception was presenting himself to her as "Ernest" when he could have just been himself, and maybe she would have taken a liking to his real name.
Jack tried to be earnest and present himself as an honest man...
when he was really "Two-Faced" the entire time.
Ok maybe that was an exaggeration.. I mean he didn't turn evil with his alternate identity.
But like Harvey Dent, Jack tried to be honest and true to the love of his life, but "being Ernest" was lying to Gwendolen, even though she fell in love with Ernest.
Cecily & Reality
While it seems that Cecily is just a teenage girl disconnected from reality, she is actually the bridge between fantasy and reality. Cecily doesn't allow deception to play a role in her life because she is able to distinguish reality from fantasy. Jack and Algernon have allowed their fantasy personas to throw their lives out of whack, but Cecily clearly separates her fantasies from reality by keeping her fantasies in her journal and not allowing them to dictate her life. She imagines a perfect reality for herself, which is far from her boring reality. She pretends she is married to Ernest in her fantasy, because she knows she cannot be with him in reality.
Her diary takes the details from reality and she spins them into her own fantasy. Her writing creates a fantasy world by taking the details she records from reality and twisting them to her imagination. In this case, the only person Cecily is deceiving is herself. She is aware of reality and knows how to keep her fantasies separate from reality, unlike Jack and Algernon. However, her written fantasies are her distortions of reality, creating a more pleasant world in her eyes.