Atheis literally Atheist, also known as Kafir is a 1974 Indonesian film directed by Sjumandjaja and adapted from Achdiat Karta Mihardjas novel of the same name. It follows a young Muslim man named Hasan who, through his interactions with others, loses his faith.
The film takes place in Indonesia in the early 1940s, covering the Japanese occupation and slightly before. Hasan Deddy Sutomo is raised a devout Muslim and, as he grows older, falls in love with Rukmini Christine Hakim, an equally devout woman. However, he finds himself intrigued with the modern Kartini Emmy Salim, whom he meets through his politically active friend Rusli Kusno Sudjarwadi. He also meets the nihilistic Anwar Farouk Afero.Through his interactions with Rusli and his friends, Hasan begins to doubt his Islamic faith. He becomes an atheist and marries Kartini. However, this drives him and his family further apart. When he discovers that Kartini and Anwar spent a night in a hotel together, he becomes enraged and hunts the nihilist. After killing Anwar, he himself is killed by the Kempeitai Rusli meets a similar fate elsewhere. ........
Source: Wikipedia