In 1984, Orwell argues that totalitarian governments pose an immense danger to society. He demonstrates this message through his portrayal of life in Oceania. The Party, which rules with absolute power, monitors the every word and action of citizens, controls the flow and content of information, and uses extreme violence to maintain authority. They are even in the process of modifying the language so that independent thought will become an impossibility.
In addition, through the character of Winston, Orwell shows that resistance to this kind of government is absolutely futile. Despite his efforts, Winston ends up in Room 101 and, eventually, gives in to Big Brother. In other words, the Party is so strong that it cannot be overcome, no matter how hard one tries.
So, Orwell's message is that a government must never be given the opportunity to take absolute power because once it does, it will never give it up.