Quite obviously, the moral of the film is that hubris (specifically, the kind that makes you clone dinosaurs and fill an amusement park with them before you even know how to take care of them) is bad. The antihero is John Hammond, a leisure-suited billionaire with childlike enthusiasm for the possibilities of genetic science. Of course, all of the main protagonists are reasonably sure that this whole "resurrecting dinosaurs" thing is a bad idea, which the movie and its three sequels all illustrate using the helpful visual aid of dinosaur-related fatalities.
But the most consistently correct character in the film is Jeff Goldblum, playing Jeff Goldblum, a mathematician who has nothing but disdain for the scientific method. In one monologue, he describes scientific discovery as "a violent, penetrative act that scars what it explores. What you call discovery, I call the rape of the natural world." That's right -- Jurassic Park is a science fiction film that refers to science as a form of rape.
Hammond goes on to joke about how the only person on his side around a table of scientists is the "blood-sucking lawyer" -- who represents the careless pursuit of wealth, and incidentally is the first person to be eaten by a dinosaur. Later in the film, Goldblum's character continues to proselytize on the folly of science's inclination toward playing God -- at one point musing, "God creates dinosaurs, God destroys dinosaurs, God creates man, man destroys God, man creates dinosaurs."