The Olympians of the Iliad know everything about the mortals they look down upon; Zeus himself is eurúopa, “far-seeing,” a direct legacy of his origins as the all-seeing God of the Bright Sky, to whose celestial vantage the events on earth are laid bare. Rarely indolent, usually zestful and opinionated, the extended family of Zeus aggressively engages with the mortal world. In disguise, the Olympians move, speak, and act freely among men, partaking of the human experience. There is nothing about the men and women at Troy that the gods do not know, even to foreknowledge of their individual fates.
By contrast, despite the busy flow of divine activity that drums through their lives, the Homeric heroes and heroines know very little about their gods. Few could claim to know what a god looks like, as most encounters take place with the deity in disguise. There are exceptions: Helen famously recognizes Aphrodite, despite her masquerade as an old servant woman, by the “round, sweet throat of the goddess / and her desirable breasts and her eyes that were full of shining.” Likewise, Poseidon’s disguise as the seer Kalchas is betrayed by his footprints: “‘this is not Kalchas, the bird interpreter of the gods,'” Aias the son of Oïleus says to Telamonian Aias, “‘for I knew / easily as he went away the form of his feet, the legs’ form / from behind him. Gods, though gods, are conspicuous.'”
By and large, however, the men at Troy fight in a kind of fog of existential ignorance, never knowing where or who the gods are or what divine activities and plans already under way may affect their own actions. Nor do they know what they must do for their supplications and prayers to be received. A very few incidents appear to suggest that Zeus, at least, punishes the wicked, which, if true, would furnish some minimal guidance for gaining his favor and avoiding his wrath. Menelaos, for example, rants at the Trojans for taking Helen away: “‘wretched dogs, and your hearts knew no fear / at all of the hard anger of Zeus loud-thundering, / the guest’s god, who some day will utterly sack your steep city.'” On closer look, however, in this and other such cases, it is clear that punishment is to be meted out by Zeus only in his capacity as patron of a specific institution: he is Zeus Orkios, “Zeus who upholds oaths,” or Zeus Xenia, the god of guest friendship. Zeus’ loyalty, then, is in fact to himself in his particular cultic aspects, not to a principle of overarching justice.
— The War That Killed Achilles, pp. 116-17