Origen composed at least thirty-two books of a commentary on the Gospel according to John, at the request of St. Ambrose of Milan. Of these, only nine books are extant in almost complete form, although we have selections of others persevered in other collections of the works of Origen. The commentary proceeds verse by verse, and is particularly notable for its emphasis on the spiritual meaning of the Gospel.

This volume contains books 1,2,6, and 10, and fragments of books 4 and 5. Origen's main interest is the allegorical interpretation of the Gospel according to John, which makes this an important work in the study of Origen's mystical thought. A secondary interest is the refutation of Valentinian gnosticism. According to Eusebius, Ambrose had been a Valentinian before his conversion by Origen, and Origen refers to the Gnostic writer Heracleon regularly throughout the commentary in order to refute his views.

Although the refutation of Heracleon may have been a stimulus for the composition of this work, Origen moved beyond this goal in order to present a commentary on the Gospel which would appeal to the growing number of educated Christians who wanted a scientific exegesis. The author's writing covers a wide range of historical, theological, philosophical and etymological topics, all focused on this Gospel of "spiritual food." "We might dare to say," Origen says as he begins his commentary, "that the Gospels are the first-fruits of all Scriptures, but that the first-fruits of the Gospels is that according to John. How great must be our understanding, that we may be able to understand in a worthy manner the word which is stored up in the earthen treasures of paltry language." The Spirit-led exegete can thus draw out of the words and symbols a higher level of insight. This "spiritual gospel" is the reality of which Christ's acts were symbols; it is the secrets hidden in the mysteries of Christ's words.