So, on one hand we've got Tartuffe. He acts like a moral authority while doing tons of immoral and unethical things: he lies, steals, blackmails, attempts to commit adultery…the list goes on and on. On the other hand, we have Cléante. He has a handle on these sorts of matters, and he's not afraid to share his opinions. He explains to Orgon why Tartuffe is full of lies, and he confronts Tartuffe personally whenever he gets the chance. Those two throw their weight around, but they're not the only ones with an opinion or two. When you encounter Elmire and Dorine, be sure to watch them carefully.
In Tartuffe, we learn that, though there are some cases where right and wrong are clearly defined, more often than not we find ourselves in a gray area between the two extremes.
However light and humorous Tartuffe may be, Molière has a real interest in teaching his audience about right and wrong.