I would like to add that all of the gods do not have it in for Odysseus- in fact he has the favor of the gods on his journey and quest for home, wife, and son. He has Athena, the goddess of wisdom and daughter of Zeus (head of all gods), who is helping him home. In fact the book states that Odysseus has the help of all the gods except one, Poseidon. Poseidon, the god of the sea is making Odysseus' journey home long, hard, and full of grief because of what Odysseus did to his son Polyphemus. Polyphemus, the Cyclops, prays to his father to make Odysseus' journey home long, difficult, and full of grief. In an answer to his son's prayer and for vengeance because his son has been blinded by a mortal Poseidon grants Polyphemus' request and since the majority of Odysseus' journey home must be taken by sea, Poseidon has the power to force Odysseus to face all these monsters and temptations.
Odysseus's problem, in terms of plot, is that he wants to return from the war to his home and his wife Penelope, who patiently awaits him. The difficulty is that the gods have it in for him, so that he repeatedly encounters difficulties (such as Polyphemus) and temptations (such as Circe and Calypso)that deter him one way or another. When he faces these problems, he must use his wits to solve them, which we see him doing again and again, making him the epitome of the epic hero. His story is that of a quest, and attaining that quest concludes the story.