Pope Gregory wrote scores of letters that circulated widely throughout Christendom, and there is one among them in which he discussed Christ’s descent into hell. He wrote to two officers of the church at Constantinople regarding their preaching that Jesus had released from punishment all those in hell who acknowledged him as God. Gregory wrote that he wanted them to believe far differently, for the truth was that Christ delivered only those who had believed that he would come and had observed his commandments. He advised them, “Only hold the true faith taught by the Catholic Church: that the Lord on his descent into hell only released from its confines those who in their fleshly existence had been guarded by his grace in faith and in good works.” This emphasis upon good works had been lacking in Augustine’s exposition on the salvation of the ancients; but absent from Gregory’s work was Augustine’s doubt over the location of the ancient elect, for he was confident that they waited in hell for Christ’s coming. However, the Pope shared with St. Augustine the belief that if Christ had preached to all the souls in hell, it would have given sinners an unjust advantage over the faithful.
Gregory buttressed his teaching with the authority of Philastrius, a IVth-century bishop who had compiled a catalogue of heresies, Diversarum Hereseon Liber. He had labelled as heretics those, such as Clement and Origen, who say that Christ revealed himself to all the souls in hell and granted salvation to those who acknowledged him there. St. Gregory noted that St. Augustine had concurred in this condemnation. In sum, Gregory’s view was that Christ descended into hell to free those ancients who had believed that he would come and had spent their lives in faith and good works. Whether he felt that this limited salvation to the Jews or included pagans as well is left uncertain in his writings.

Ralph V. Turner. ‘Descendit Ad Inferos’: Medieval Views on Christ’s Descent into Hell and the Salvation of the Ancient Just. Journal of the History of Ideas, Vol. 27, No. 2 (Apr. – Jun., 1966), pp. 178-179.