Every so often, spiritual lightning sears across a culture's landscape. The example of St. Francis of Assisi immediately comes to mind. So does St. Antony. Their intense holiness was bright and powerful, and left an indelible mark on the earth.
We can't know for certain why God sends these religious jolts when he does, but we can assume he has some purpose. St. Francis, for instance, came at a time when Europe was emerging from the Dark Ages. European wealth and power and prosperity surged in the twelfth century, and with it came temptations to greed and vice. St. Francis cut against the wealth and power by opting for no property and no control. His was absolute poverty at a time when poverty was becoming a dirty word.
He, with St. Dominic (his spiritual twin brother), spawned new religious orders of poverty-embracing friars and paved the way for the thirteenth century, a time when the Catholic Church produced some of its greatest cultural contributions. It is no coincidence that the century's greatest thinkers, St. Thomas Aquinas and St. Bonaventure, belonged to the Dominican and Franciscan Orders, respectively.
St. Antony, too, appears to have come at a particular time for a particular reason. He went to the desert shortly before Christianity became the institutionalized religion of the Roman Empire.
Before its ascendancy, persecution and martyrdom were never far away, and the possibility of a violent death hung over the heads of the faithful, pressing them to a life of virtue. But after Christianity was implanted as the official religion, martyrdom was no longer available.
A new form of heroism was needed, and tens of thousands found it in the desert struggles that Antony showed them. The martyrdom that gave a strong backbone to early Christianity was replaced by the asceticism of the desert, and Christianity's backbone was strengthened further.
In the late nineteenth century, another spiritual lightning bolt hit Western culture. St. Therese of Lisieux, the Little Flower. Like Francis and Antony, I think she came for a reason: To show the modern era a path to holiness.