Perhaps I should add to my part in the discussion, to do Ingmar Bergman justice, that "Through a Glass Darkly" is an incorrect translation of the original Swedish title for the film. Translated word for word, it would have been called "Such as in a mirror", but that doesn't ring well in English so the producers used the other title. And I am not sure that Bergman actually mentioned the Bible in the interview.
Here is an excerpt from Wikipedia on the film:
"The title is from a biblical passage (1 Corinthians 13) in which seeing through a glass darkly refers to our understanding of God when we are alive; the view will only be clear when we die. The Swedish title literally means As in a Mirror, which is how the passage reads in a 1917 Swedish translation of the Bible."
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en.wikipedia.org])