ABSTRACT: This essay examines the difference between Voldemort's father's 'sacrifice', the 'bone of the father' and Harry's mother's sacrifice, the 'blood of the enemy' and discusses how and why they are different and whether one form of protection is better than the other.
'You stand, Harry Potter, upon the remains of my late father,' he hissed softly. 'A muggle and a fool... very like your dear mother. But they both had their uses, did they not? Your mother died to defend you as a child...and I killed my father, and see how useful he has proven himself in death...' (p 560 GOF UK)
Voldemort returns to his body by aid of a spell that requires the 'bone of the father, unknowingly given'(p 556 GOF UK). By taking a part of his father's body, Voldemort is able to return to full strength and prolong his life, however, this is not the first, nor is it the most significant display of parental sacrifice that takes place in the series. Harry is chosen to provide the 'blood of the enemy' (p 557 GOF UK) precisely because his life has been prolonged by his parents sacrifice. Parental sacrifice is a key theme in the Harry Potter series and Harry becomes the hero he is as a result of his parents' deaths. The choices parents make and the sacrifices they are willing to make for their children impact greatly on their children as shown through Harry and Voldemort.
When Lily Potter sacrificed her life for Harry's, not only did she prolong his life by saving him from Voldemort's spell, she also prevented Voldemort from touching Harry. Lily Potter's sacrifice is similar to Tom Riddle Sr.'s in the sense that they both 'unknowingly' prolong their children's lives, however a crucial difference remains: although they may have 'unknowingly' helped their children one of them willing sacrificed themself.
Lily Potter didn't stand between Harry and Voldemort because she was aware of the magic she was invoking by sacrificing her own life, however she willingly risked her life despite the fact that she didn't know whether her sacrifice would spare her son. Tom Riddle Sr. on the other hand left his wife before his baby was born; he never met his son and in fact wanted nothing to do with him. Tom Riddle Sr.'s life was sacrificed unwillingly in order to create one of Voldemort's horcruxes, Voldemort murdered his father in order to attain immortality and later stole his father's own bones in order to create himself a new body.
Although Voldemort promotes anti-muggle beliefs, both of the parents in question were of non-magical parentage and yet both provided powerful magical protection for their children. Lily's choice to risk her life for Harry provides a key protection that not only saves Harry's life but enables him to vanquish Voldemort at the end of Philosopher's/ sorcerer's Stone. Her protection also enables Harry to return from King's cross in the final novel and thereby saving his life again.
Tom Riddle Sr.'s death by his son's hand allowed Voldemort to create a horcrux which provided him with protection and enabled him to remain alive, in a sense, when the curse he aimed at Harry rebounded. However, unlike Lily's protection, which lives on not only in Harry but also in Voldemort once he has taken Harry's blood, Tom Riddle Sr.'s protection can indeed be destroyed. The same can be said for the bone's which enable Voldemort's return, although Tom Riddle Sr.'s bones prolong Voldemort life, the body he creates is worthless once he has been killed.
The crucial difference between the two parents reflect the difference between the children - Harry accepts help from others and uses the sacrifice his mother makes to empower him, while Voldemort, who surrounds himself with death eaters, does not trust or rely on anyone. Instead, he uses people for his own means and therefore only receives protection by forcefully taking it. In light of this it is clear to see that Harry's protection is much stronger and much more useful to Harry than Voldemort's.