Origen did not invent the idea that one must pursue purity of heart in order to understand the deeper spiritual meanings of Scripture. But his teaching ministry at Alexandria in the early third century gave this idea a deep and longstanding influence in the church.

In spite of the vying claims of Athens and Antioch, Alexandria served as the intellectual center of the Roman Empire at that time, and it was the Alexandrian synagogue that had first translated the Old Testament into Greek. The church at Alexandria was the heir to both of those traditions. Consequently, the other churches recognized the Alexandrian church as, in many ways, their teacher.

Following his predecessor, Clement, who died in 215, Origen established the exegetical standards of the church in Alexandria.

From its catechetical school would come forth some of the most famous names of Christian doctrinal history, such as Athanasius, whose teaching guided the Council of Nicaea in 325, and Cyril, who dominated the Council of Ephesus in 431.

It was from the church at Alexandria that Christianity's first monks went out to the Egyptian desert, taking with them the great teacher's deep insights into the reading of the Bible and the quest for holiness. The lives and writings of those Egyptian monks—including Nesteros—became authoritative for all of Christian monasticism.

Nesteros's exegetical approach might never have left the sands of Egypt, except for a Romanian monk who happened to be visiting the place sometime just before 400. His name was John Cassian.

After he left Egypt, Cassian went up to Constantinople, where he became the deacon for that city's new bishop, John of Antioch, better known to history as John Chrysostom (437-407). (Cassian thus became a living link between the Alexandrian and Antiochian schools of biblical interpretation.) Later he went west to Rome and finally to Marseilles, in the south of Gaul, where he served as the abbot of a large monastic community.

Living at Marseilles until his death in 435, Cassian also found time to write books, and one of those books, called the Conferences, contained the teaching of Nesteros on the four senses of Scripture. A century later Benedict of Nursia, in the final chapter of his monastic rule, recommended the writings of Cassian to his monks, and for the next thousand years those monks zealously followed his recommendation.

—Patrick Henry Reardon