In Chapter 23 of the Lotus Sutra we find these twelve similes:
This sutra can bring great and abundant benefit to all the living and fulfill their hopes.

Just like a clear, cool pool, it can satisfy all who are thirsty. Like fire to someone who is cold, like clothing to someone naked, like a leader found by a group of merchants, like a mother found by her children, like a ferry found by passengers, like a doctor found by the sick, like a lamp found by people in the dark, like riches found by the poor, like a ruler found by the people, like a sea lane found by traders, and like a torch dispelling the darkness this Dharma Flower Sutra can enable all the living to liberate themselves from all suffering, disease, and pain, loosening all the bonds of mortal life. (LS 359)

This passage can readily be understood to be not only describing the wonderful powers of the Dharma Flower Sutra but also expressing hope for all those in need:

May those who are thirsty find cool, clear water.
May those who are cold find a warm fire.
May those who are naked find clothing.
May those who are without leadership find a leader.
May children who are lost find their mothers.
May those who need to cross over water find a ferry.
May those who are sick find a doctor.
May those who are in the dark find a lamp.
May those who are poor find riches.
May those in need ofone find a ruler.
May those who trade find a sea lane.
May those in darkness find a light.

In other words, the twelve similes are not merely claims about what the Lotus Sutra can do, though they are that; they are also a poetic expression of the many kinds of human needs and of the hope that they be met.

Thus the meaning of “this sutra can save all living beings” is that if it is heard and applied – by us – people will be saved. Those who are thirsty will find cool water and those in the dark will find light.