What is the main message of Huck Finn?

What do you believe is the central message of the novel "The Adventures of Huckleberry Finn" by Mark Twain? Is it about the importance of individualism and personal freedom, or the harsh realities of slavery and racial injustice in the American South during the 19th century? Or is it a commentary on the hypocrisy of society and the adult world? How does the protagonist Huck Finn's journey reflect on these themes and issues?