Voldemort wanted to kill Harry Potter because of a prophecy that foretold a child who would have the power to defeat him. Voldemort chose Harry as the target because he saw Harry as a threat and considered him his equal. The prophecy suggested that the "Dark Lord will mark the chosen one as his equal," meaning Voldemort's actions to kill Harry actually made Harry the one destined to challenge him. Additionally, Harry's parents had defied Voldemort multiple times, making their son an even greater threat in Voldemort's eyes. Voldemort also killed Harry's parents to get to Harry and eliminate his obstacles. Furthermore, Voldemort underestimated the power of love, as Lily Potter's sacrifice to protect Harry created a magical protection around him that Voldemort did not anticipate. This act of love caused Voldemort's killing curse to rebound, marking Harry with a lightning scar and embedding a piece of Voldemort's soul inside him, making Harry a Horcrux. Voldemort's inability to understand this power of love and sacrifice was a critical weakness that ultimately contributed to his downfall. In summary, Voldemort wanted to kill Harry to prevent the prophecy from coming true, to eliminate a powerful threat, and to prove his superiority, but his own choices and the protective sacrifice of Lily Potter led to his defeat instead.