Through a Glass Darkly is interesting if for no other reason than Bergman didn't seem to really care for it all. One could chalk it up to the usual case of the artist's self-deprecation, but when reading his book Images:
My Life in Film you understand that Bergman had a different film in mind before he shot
Through a Glass Darkly, and the result — which is certainly one of the most seminal foreign films of the '60s — was not to his liking. I think Bergman is too hard on himself and critiquing the movie he had in his head instead of the one he actually filmed. What's important about this film, aside from helping Americans ingratiate themselves into the foreign film world (along with Fellini and Antonioni), is that it marks a shift in tone for the auteur. With
Through a Glass Darkly, Bergman worked out the kinks and used its aesthetic and its themes as a catalyst for what would be the Bergman tableau that everyone recognizes today.