Hesiod's Theogony concerns creation. More specifically, the title Theogony means birth of the divine, and Hesiod relays the creation myths concerning the birth of the gods. He describes the creation of the cosmos, or universe, as being very orderly, and even the birth of the gods formed a unified whole; however, he also describes the gods' actions as being chaotic, even devious. Throughout all of the myths is the underlying idea that the actions of the gods are chaotic and evenly morally questionable. One example can be seen in Book VIII in which Cronos swallows his kids to prevent power from extending to the next generation. The gods giving birth to evil things, such as Medusa and other monsters, also calls into question the gods' behavior, showing us that they are generally immoral and non-harmonious. Hence, one dominant theme in Hesiod's Theogony is the chaotic and even immoral conduct of the gods.
Homer also presents the gods as behaving immorally. One example can be seen in Zeus's actions in the Iliad. Agamemnon steals away Achilles' war prize, Briseis, as restitution for having been forced to return his own war prize, Chryses, to her father, the priest of Apollo, due to plagues Apollo sent to punished the Greeks. As a consequence, wounded, Achilles goes to his mother, the goddess Thetis, to beg Zeus for revenge. Zeus agrees and begins supporting the Trojans in the Trojan war, leading to many innocent deaths among the Greeks. Had Zeus been acting as a more just, all-knowing god in control of creating a unified whole, he would have not agreed to take lives for such a petty motive as revenge. However, as Homer points out, revenge is a driving force among the gods that continually creates chaos. In contrast to Hesiod, however, Homer's themes concern the immoral actions of mankind as well as the gods, such as Agamemnon's act of stealing a war prize out of petty jealousy and pride and Achilles' act of causing thousands of deaths due to the petty desire for revenge.
Likewise, Sophocles also uses the actions of the gods to point out the importance of revenge to the gods and to show that the gods' actions continually causes chaos; however, in contrast, like Homer's works, Sophocles' plays focus more on the moral/immoral actions of humans rather than of the gods. Sophocles' themes in the Oedipus trilogy point to all sorts of human follies, such as pride, arrogance, and stubbornness. One specific example can be seen in how Sophocles paints Creon as a foolishly prideful and stubborn character in Antigone. It is due to his pride that he decides to pass a law forbidding the burial of his fallen nephew Polynices due to his nephew's attack on Thebes; more importantly, Creon passed this law despite the fact that the gods already had their own law commanding that respect be paid to the dead. The soothsayer Tiresias best describes Creon's guilt of pride and stubbornness in his lines, "Obstinacy brings the charge of stupidity. Yield to the dead, don't kick a fallen man! What prowess does it take to kill one already dead?" (1031-34). Hence, one great contrast between Hesiod, Homer, and Sophocles is that both Hesiod and Homer judge the actions of the gods, while Sophocles spends more time on judging the actions of man. However, Sophocles too brings into question the actions of the gods, particularly when he brings up the theme of fate. In Oedipus Rex, it is apparent that Oedipus's own pride and foul temper helped lead to his downfall; however, fate certainly does play a dominant role. The play states that the gods destined Oedipus to sin against them by murdering his own father and marrying his own mother. Hence, the theme of fate also calls into question the gods' actions by raising the question, what kind of gods will mankind to sin against them, creating chaos?
Hence, dominant themes in Hesiod's, Homer's, and Sophocles' works concern the chaotic, immoral actions of the gods, as well as the immoral actions of mankind, as we see in both Homer's Iliad and Sophocles' plays.
One of the best answers I have ever received. Thanks for such thoroughness! ss