Harry Potter and the Deathly Hallows contains multiple archetypal themes throughout the course of the novel:
Harry, Ron, and Hermione are on a quest to save the Wizarding world by destroying Voldemort's horcruxes.
Through Harry and ultimately Severus Snape, the novel explores what it means to be a hero, examining the attributes of self-sacrifice, dedication, and courage.
Although Voldemort would certainly pose as the dominant obstacle in the novel, Harry, Ron, and Hermione must overcome multiple challenges in their quest to find the horcruxes, like breaking into Gringotts, infiltrating the Ministry of Magic, and making their way back to Hogwarts.
Death and Rebirth:
This theme figures largely in the end of the novel as Harry struggles with the true meaning of the prophecy: "Neither can live while the other survives." Harry willingly faces Voldemort on the end and is on the receiving end of Avada Kedavra, but lives to overcome him after meeting with Dumbledore in a mystical King's Cross dream world. He remains "the boy who lived."