Primer (2004) cost only 7 grand to make, but is one of the best suspense/sci-fi movies I've ever seen. It's also a mind-bending experience like "Inception" and "Memento" and could require additional viewings or a rush to the Internet to figure out everything that's going on here. But it's a wonderful, trippy experience. (It's also available, either in parts or as a whole, on YouTube.)
The obvious Nativity subtext aside, I don't think of this movie as commentary about the future; it's about every generation. Past, present and future. The signs are all there. The idea isn't religious; it's universal, all faiths and beliefs. We see what we want to see in art, our own beliefs and our own thoughts reflected back on us. What this film does is it crosses boundaries to mix all together about one single idea that brings them into one, four-lettered word: hope.