The movie storyline seems a little like Heart of Darkness. The main character is procrastinating in an hotel (?) watching TV shows, the world around seems in decay. He's send to a remote place where something happened (people cured from disease?, meteorite?, alien?), goes there, there is a resurgence of religious faith among the villagers, The hero wanders in the desert, psychedelic scenes like 2001 but less colorful... I don't remember much of it, I saw it in the nineties, but vivid images, looks sometimes a bit like Stalker. Made me also think of Chernobyl, maybe it was shot just after. The opening scene might have been shot on the shores of the Aral See, but not sure.
I keep looking for this movie, seems unable to find out what it is