In some ways, our biggest challenge in gauging Jesus' influence is that we take for granted the ways in which our world has been shaped by him. For example, children would be thought of differently because of Jesus. Historian O. M. Bakke wrote a study called When Children Became People: The Birth of Childhood in Early Christianity, in which he noted that in the ancient world, children usually didn't get named until the eighth day or so. Up until then there was a chance that the infant would be killed or left to die of exposure — particularly if it was deformed or of the unpreferred gender. This custom changed because of a group of people who remembered that they were followers of a man who said, "Let the little children come to me."

Jesus never married. But his treatment of women led to the formation of a community that was so congenial to women that they would join it in record numbers … Jesus never wrote a book. Yet his call to love God with all one's mind would lead to a community with such a reverence for learning that when the classical world was destroyed in what are sometimes called the Dark Ages, that little community would preserve what was left of its learning. In time, the movement he started would give rise to libraries and then guilds of learning …

He never held an office or led an army … And yet the movement he started would eventually mean the end of emperor worship, be cited in documents like the Magna Carta, begin a tradition of common law and limited government, and undermine the power of the state rather than reinforce it as other religions in the empire had done. It is because of his movement that language such as "We hold these truths to be self-evident, that all men are created equal; that they are endowed by their Creator with certain unalienable rights" entered history.

The Roman Empire into which Jesus was born could be splendid but also cruel, especially for the malformed and diseased and enslaved. This one teacher had said, "Whatever you did for one of the least of these, you did for me." An idea slowly emerged that the suffering of every single individual human being matters and that those who are able to help ought to do so. Hospitals and relief efforts of all kinds emerged from this movement; even today they often carry names that remind us of him and his teachings.

Humility, which was scorned in the ancient world, became enshrined in a cross and was eventually championed as a virtue. Enemies, who were thought to be worthy of vengeance ("help your friends and punish your enemies"), came to be seen as worthy of love. Forgiveness moved from weakness to an act of moral beauty. Even in death, Jesus' influence is hard to escape. The practice of burial in graveyards or cemeteries was taken from his followers … It expressed the hope of resurrection … Death did not end Jesus' influence. In many ways, it just started it.