Avatar spoke out against racism, much like District 9 did, but with much more emotion. It criticized the War in Iraq heavily, even using the phrase "shock and awe."
But the film did have one message that can be absolutely deadly. One of the central themes is the doctrine of pantheism. Pantheism holds that all creatures are connected in to one central being. That god is part of everyone and everyone is part of god. On the moon Pandora, the setting for Avatar, all creatures live in harmony with each other and their god, Erya. Erya is in all creatures, and all creatures are in Erya. Classic pantheism.
As with any kind of false theology, there is a false hell and false heaven. The false heaven is nature in harmony with itself. When there is balance there is peace, and all creatures can live happily in unity with Erya.
The false hell taught is, of course, the opposite. Humans come to Pandora and bring heavy machinery to mine, and guns to make the natives submit. The functional hell the movie creates is a life out of unity with nature. The savior that bridges the gap are the characters in the movie.
All they have to do is go back to nature to gain heaven.
Ok, that's really simplified but if you look its in the movie.
That's not in the Bible.
The Bible teaches that heaven is real, a place where one lives in eternal fellowship with God. Hell is the place of eternal separation from God. Sin is what separates heaven from hell. The only thing that can take us from hell to heaven is Jesus. That's the gospel.
I'm not saying Avatar is a bad movie. It's thoroughly enjoyable and I will watch it again. But it is dangerous. Christians have to be aware of and spot false theology, and not let it ruin a good movie.