Theorem   Pier Paolo Pasolini  (1968; It,15) Silvana Magano, Terrence Stamp

https://www.youtube.com/watch?v=oCGVIg1ksYU

Written and directed by Pasolini Thoerem is themed about the divine and corrupt. 

Terence Stamp plays a mysterious otherworldly figure known only as 'the visitor' who appears in the lives of an an upper middle class family in Milan,; then just as abruptly disappears. It's an exemplary, beautiful and strange doorway into the heart of Pasolini. Almost wordless, relying on exquisite framing and body language. 

This may or may not be of interest: https://www.maramarietta.com/the-arts/cinema/t-v/teorema/