Dionysus, also known as Bacchus, is the son of the god Zeus and Semele. He is known as the twice-born god because Zeus unintentionally burned Semele on the account of Hera's trickery and Dionysus died inside Semele. There are a few stories that come to his rebirth but the one that is most remembered in mythology is that Hermes took the heart of Dionysus and sew it into Zeus's leg. After much persecution by Hera, Zeus finally became fed up with it and turned Dionysus into a god. .
Dionysus was the god of many things and some think that he is the most important god out of all of them which I for one agree with. To start he was the first god of fertility associated with plants and animals. For this he was known as "he of the trees". He is also the god of wine, he had discovered this when he was in Nysa, also known as god of blossoms. .
This is where things get confusing. Dionysus is associated with both the life force and with death. He brings death, madness, and destruction to every where he goes and everyone that follows. However, paradoxically resurrection and life as well. For example; Dionysus drove Ino, his nurse, insane and she boiled her child alive, however she jumped into the sea and became a sea goddess. His mother, Semele, was burned alive but she joins Dionysus and other gods at Mount Olympus. By creating destruction in a way he is also creating life. .
Dionysus played an important role in helping life go on. He is the god of wine which in those days was a major thing to the Greeks and stimulated not only self worth and peoples lives but also stimulated procreation. The people that followed him would go mad, they would have parties and drink and let themselves go free without the common day worries and let life live. He is a god of the people. He understands them and the people that were his followers had a piece of him inside of them. He understood death like no other god could because he is the only god that dies and comes back.