There are many elements that need to be examined individually to understand a greater part of the comedy at hand.
First, the dedication of the play made to Robert Baldwin Ross. Wilde called Ross, ‘the Mirror of Perfect Friendship.’ One has to wonder if this is a semi-anecdotal work. Or if the dedication is just that, a dedication? Personally, it would be nice to know more about Wilde's background, in particular - his friendship with Ross.

Also, there are issues of religion all through out the work: issues with being baptized with the proper name, Ernest; “manna in the wilderness,” sent from God to the Isrealites after escaping Egypt (Exodus 16); and issues about what “a man sows, so let him reap” (Galatians 6:7). It is interesting to note, that two of the aforementioned deal with the nature of escape or change. Algy and Jack wanted to be baptized in the Catholic church as men named Ernest because that is what their female admirers so longed. Chasuble prepares a sermon about the escape of the Isrealites from Egypt, in which God provides for them. Many of the characters in the story are trying to escape themselves, but eventually return full circle to realize what they are escaping in the fiber of their being. They learn lessons on moral character, which is something they repeatedly reference in the work. In all actually, they learn the importance of being earnest. Which characters are round characters in the work? Flat?

http://blogs.setonhill.edu/DenamarieErcolani
I said a little something here!!

Lady Bracknell is such a cold old woman. She doesn't even care about her husband's failing health and even mentions how much younger Lady Harbury looks after her husbands death. The fact that she shows no sympathy towards Ernest for being a foster is amazing. All she wants him to do is find one of his parents.

Katie: your observation of the characters as "flat" makes a lot of sense. Did you notice the very last thing that happens in the play? Do you know what a "tableau" is?

Sean, why would Wilde have created a character such as Lady Backnell? I believe she's the only married character in this comedy (in which three pairs of characters pursue romances). What is Wilde suggesting about marriage?