We actually don't have a complete copy of this play though the edition that I read attempts to reconstruct the missing sections (which is mostly at the end) because, as they say, this is a popular play that is regularly performed. This in itself is a strange statement since I have never seen it performed (in fact I have only ever seen one Greek play performed, and that was Oedipus Tyrannous and that was by an amateur theatre group). Mind you, Greek plays tend to be short, meaning that they last generally only as long as about a third of a Shakespeare play (though when they were performed in ancient times, it would usually be along with three others plays).
The Bacchae is about change and about the resistance to change and how our attempts to resist change is generally futile. Mind you it is a tragedy and it does have a pretty bloody ending (in that a number of the main characters end up dead, though the progenitor of change, Dionysus, doesn't, but then again he is a god). There are two things that do strike me about this play, the first being how there are reflections of Christianity in it, particularly early Christianity, and the second involves reflections of the modern rave culture. However, before I go into exploring those two aspects of the play I should give a bit of a background so you may understand where I am coming from.
The cult of Dionysus was a rather new cult to appear in Ancient Greece, as far as the gods are concerned, and he was not one of the traditional gods of the pantheon. He apparently was introduced through migrations from the north, particularly through Thrace. The cult itself was a mystery cult, meaning that the rituals and celebrations tended to be conducted behind closed doors (and this comes out in the Bacchae, particularly since the main worshippers were women). The celebrations (as also comes out in the Bacchae) generally involved drunken revelries out in the bush.
The Bacchae itself is set in the mythical period of Ancient Greece in the city of Thebes. The king of Thebes, Penthius, is concerned about this new cult that has appeared that is seducing all of the women into joining. As such he goes out of his way to attempt to put an end to it, including arresting Dionysus. It is interesting that Dionysus, unlike the gods in many of the other Greek plays, has a major role. Most of the gods in Greek drama tend to only come in at the beginning or the end, either to provide an introduction, or to intervene in a hopeless situation. However Dionysus is one of the major characters in this play.
Anyway Dionysius, in an attempt to defend his cult (and one wonders if his portrayal here is similar to the charismatic cult leaders that we have seen throughout history) convinces Pentheus to spy on one of the celebrations. However, in a drunken haze, the women in the midst of their celebration mistake Pentheus for an mountain goat, capture him, and tear him to pieces. However, the women do not get away scot free as they are exiled for, well, murder, despite their arguments that they were not in control of their faculties at the time.
The idea of the new cult is something that societies have faced throughout time, and it goes to show that the Roman persecution of Christianity is something that is not limited to that particular religion at that particular time. It is interesting to note that in the play Pentheus does not believe that Dionysus is a god, despite certain actions (such as blowing up his palace) that suggest otherwise. Further, the ignorance of the bacchic rites is also similar to Roman ignorance of certain Christian rites, such as the Lord's Supper.
Some have even suggested that Dionysus is a Christ figure, and the introduction to the play even has some similarities with the virgin birth. For instance, Dionysus is born of a woman but has Zeus as his father (though unlike Christianity, where the term 'conceived of the Holy Spirit' does not indicate a sexual union between God and Mary, where it is clear from this play that there was a sexual union between Zeus and Dionysus' mother, though this can be put down to our failure to understand, or accept, the possibility that conception can occur outside of sexual union, though these days this is changing). More interesting is that Dionysus mother is accused of extra-marital sex, which Mary also faced. Another interesting note is that after Dionysus' birth, Zeus hides him to protect him from being killed by a jealous Hera, which has reflections in the Christ story in that Jesus was spirited off to Egypt to protect himself from the murderous rampages of a jealous king.
Some might suggest that I am drawing some rather tenuous examples here, but I would argue otherwise. One of the reasons is generally because of the fear of Christians to look outside the box. We are more than happy to accept the Bible, but to consider anything outside of that, particularly with regards to pagan representations (or could they be prophecies) of the Christ, can open up to many probabilities. I guess it has to do with the conservative bent that most Christians have, in that what has been done over hundreds of years has proven itself and anything that is new can be dangerous or even destructive. However, remember what Paul writes in the book of Thessalonians: test everything, hold onto what is good, and reject what is bad. He did not say 'reject everything' but to 'test everything' which includes age old traditions.
I want to finish off with a comment on the modern rave scene. Okay, the idea of the outdoor rave out in the bush rose out of Britian where, in an attempt to stamp out drug use, the government made raves themselves illegal. However, it could also be suggested that the reason the mystery cults of ancient Greece met out in the bush was because they were also illegal. However (particularly since I have been to raves myself) there is something almost bacchic about the rave. The idea of taking drugs to induce feelings of pleasure, as well as the lights and the sounds adding to that, reflects what was occurring here in the Bacchae. In many cases, the rituals were sensual experiments in pleasure, which is similar to what happens at a rave. This also goes to show that the rave is not something new, but something that has been going on for centuries.