What is Harry's Secret Weapon?

[gregtaylor02]

No: HPFGUIDX 167956

In general terms, the power (love) that Voldemort knows not means that
when he attempted to kill Harry with the killing curse, Voldemort
wouldn't know that Harry would be protected by a blanket of his mother's
love.  This is the reason he must return to #4 Privet Drive each year
(summer).  The love of his mother's blood protects him if he returns
there and can call it home, for the same blood is found in Aunt
Petunia.

In the future it is unclear what power love will play but small things
throughout the books have shown that Harry's ability to love has been
in part why he is Gryffindor and not Slytherin, why he is not tempted
by the dark arts in the extent Tom Riddle was.  Harry's ability to love
is the reason he Voldemort also was unable to stay inside Harry in the
scene by the fountain with a fight between Dumbledore and Voldemort.
Voldemort tried to enter Harry's body and told Dumbledore to kill them
both, but he could not stay in there because Harry's ability to feel
love was too intense for Voldemort.  As I said it is unclear what role
it will (if any) beyond these events love will play in Harry's
adventure.

gregtaylor02