An interesting idea that sort of floats around in the back of One Piece's themes is that people make their own miracles. Willpower is a literal superhuman ability in the One Piece world, and later on Iva will say that their hormone treatment with Luffy is useless if he doesn't have the will to stay alive.
Constantly throughout the series people are expected to try before they can be saved. Luffy fights Alvida after Coby insults her. The Straw Hats help save Usopp's village from Kuro after he displays his own willingness to put his life on the line. The people of Skypiea pray for salvation after rejecting Enel's rule and attempting to flee, and the Revolutionaries only fight for civilians who are first willing to fight for themselves.
This isn't to say that people are expected to do things alone. Luffy would have absolutely been murderkilled if not for the actions of Bon-chan and Ivankov. But he absolutely has to fight with everything he has to stay alive, and in doing so makes the miracle of his own survival come to pass.
It's an interesting balance the series has maintained, dancing between the collective need for people to depend on each other to achieve their dreams and the individualistic push to start dreaming in the first place, and one that I think works quite well.
