Final answer:
Azrael's main argument in Faustus' trial is likely to advocate for divine punishment for Faustus' sins, reflecting the eternal struggle between good and evil.
Step-by-step explanation:
The main argument of Azrael in the trial of Faustus' soul centers on the concepts of justice and retribution within the spiritual realm. Azrael, as an Angel of Death in various religious traditions, would present a case advocating that the soul of Faustus, who has committed grievous sins through his pact with the devil, should receive divine punishment. This notion aligns with concepts of cosmic justice and the role of divine beings in the dispensation of penalty for sins, reflecting the eternal struggle between good and evil. However, this scenario may vary depending on the interpretation or adaptation of the play in question, such as Christopher Marlowe's Doctor Faustus or Goethe's Faust.