Vigil and Navigator are both excellent, both deal with spirituality, both contain many striking visual moments.
Vigil has a timelessness similar to films from Europe that take place in rural, isolated, or preindustrialized villages. The clothing in the film does not seem modern at all, making me wonder if kiwis actually dressed like that in the 20th century. Vigil places more emphasis on visual storytelling (or moodsetting) because the dialogue often seems incidental.
Navigator has plenty of dialogue and a clearly defined plot. Of course it's still unconventional compared to typical cinema offering. And Navigator probably has stronger imagery than Vigil, with many beautiful scenes like the one in this clip.
So certain aspects of Vincent Ward's early work reminds me of Bergman, Tarkovsky, Valley of the Bees, Witchhammer, maybe Hard to be a God as films with a similar aesthetic and content. That's the first things that came to mind, I'm sure there are other comparisons to be made...