Every human being on the face of the earth is descended from one man. The Bible says so, and there's even some genetic evidence to support it. But what concerned the sages of the Talmud most about this phenomenon was: What does it mean? What is its practical relevance to how we lead our lives?

The Talmud offers several insights. First, and most obvious, is the lesson that each and every individual is of equal worth: "Every man was created equal" is not just a conviction, but a fact. As the Talmud puts it, "No man can say to his fellow, 'My ancestor was greater than yours.'"

Secondly, the value of life. "Whoever destroys a single life, it is as if he destroyed the entire world; and whoever sustains a single life, it is as if he sustained the entire world."

Thirdly, it's a reflection on the singularity of the Creator. Fourthly, it's a demonstration of the infinite diversity latent within that singularity (every human being is descended from one person, yet no two are exactly alike!).

Finally, it's a profound lesson in the power of the individual. In the words of the Talmud, "Every man is obligated to say: 'For my sake the world was created.'" As the Torah tells it, G‑d spent six days making a universe, creating physicality and spirituality, time and space, matter and energy, water and earth, stars and trees and animals — and then created a single human being (subsequently split into male and female halves) and said to him/her: "All this is to serve you."

That man — called Adam, "man" — is every man. A finite plane has but one center; in an infinite plane, its every point is its center. In this world of infinite potential that G‑d created, each and every one of us is the very center: the focus of His creation, the force that brings it to fulfillment.

We've all just witnessed, with awful clarity, the power of the individual. How a single person, armed only with little more than utter determination, can destroy the lives of thousands and wreack havoc in the lives of millions. But the Torah assures us that the power to do good is infinitely greater than the capacity for evil.

Every man is obligated to say: "For my sake the world was created."