Every human being contains a soul, a divine spark, and therefore every life has infinite value. Therefore the Talmud teaches that saving a life is like saving a universe. Since every human being has a soul, there is a basic equality amongst all. Since every human being has a soul, then we have the obligation to be like G-d, to emulate the Almighty. Our Sages say, just as G-d is kind and merciful, you too should be kind and merciful.
Every human being is responsible for the world.