When Blok and Death interrupt their game of chess (due to the plague, Death is very busy), he meets two actors, Jof and Mia, with their little son, the most human characters of the film, and I don't think it's a coincidence that there names sound very much like Joseph and Mary. These people may be a little dim, but they are good at heart and you can see the happiness in Antonius' eyes when he is together with them for the first time.
But the main aspect of Ingmar Bergman's arguably best film are Antonius Blok's grim encounters, as the young girl about to be burnt at the stake, as a scapegoat for the plague. And the haunting image of a huge crowd of flagellants interrupting a play of Jof and Mia and trying to convince the crowd thery are doomed; hardly any other film is that direct in asking controversial and essential questions about God, religion and mankind as The Seventh Seal.
Another reason for the impact this almost 50-year-old film has still today is the acting: Max von Sydow's face always seems to reflect what Antonius Blok is thinking, Nils Poppe's performance as the naive actor and caring father is priceless and Bengt Ekerot's Death became a part of film history and survived all its spoofs (the best one being in Woody Allen's tremendously funny "Love and Death"). But the best performance is done by Gunnar Björnstrand as Antonios Blok's misogynist squire, dryly commenting all their encounters even in the face of death.
The Seventh Seal is not subtle in raising it's questions, that's for sure. But it makes you think about these questions nevertheless. It's disturbing and grim most of the time, but at the end it gives you the hope that it might become better.