Several characters in the play All my Sons believe in forces outside their control that influence the events of their lives. Please discuss the significance of this theme.

The characters in All My Sons who most believe in forces beyond their control are Frank Lubey and Kate Keller.
Frank is portrayed as a believer in astrology. He enjoys making people's astrological charts. At Kate's behest, he makes one for her son Larry and interprets it to mean that he could not be dead.
Kate is clinging desperately to the belief that her MIA son is still alive. Her faith in his survival has long ago passed the limits of any reasonable expectation. Kate has adopted a fatalistic belief in the idea that he escaped alive when his plane was shot down. Her interpretation of God is that he would have protected her son, especially if Joe was responsible for the plane's malfunction.
Kate constantly interprets everyday events as signs or portents. Her beliefs tend toward the occult, and she asks Frank to make Larry's chart.