The motif of deception
Each of the four main characters lies to the other ones. Even the father of the bride, Monsieur Orgon, pulls his own little prank on his daughter by not disclosing what he knows to her. This theme is not intended as a evil or harmful one, but rather it merely shows that we are always pretending to know who we are, but somehow, even though the kids all try to be someone else, they can't help but be themselves.
The motif of identity
The kids all mess with each other's ability to know who is who. This is a safety mechanism, a defensive way to protect them from vulnerability, but ultimately, the prospect of love is overwhelming, and they can't help but be honest about who they are, because they want to be loved for who they really are. When they do, they find out that most of the pain of intimacy was self-inflicted.
The couple as an allegory for first love
This story is allegorical because it represents something that is universally true. Humans experience shyness in their first love, and they make mistakes, and they have to figure out who they are again. But ultimately, any attempt to deceive or control the situation won't work. The inevitability of life is undeniable, and ultimately, everyone must fall in love, even though the prospect of true vulnerability is terrifying.
Love as the symbol of adult responsibility
Instead of being a gift, love is an obligation to these young lovers. They weren't exactly excited about the prospect of marriage from the get-go, especially not marriage to someone they don't know. That is very like the adolescent attitude toward life in general. Unwilling to commit and take responsibility, many young people flinch, but that's alright, because as the play suggests, life has a way of walking them through that transition, and when they've succeeded, the reward is communion.
Marriage as the reward for vulnerability
Many young couples don't seem to get through the first phase of the relationship where each person is trying to figure the other one out without really opening themselves up and becoming vulnerable, but the play is clear that marriage is the symbolic reward for vulnerability, because it means that you don't have to be alone anymore.
