From 790 until his death, Nestorios occupied the episcopal see of Beth Nuhadra. Before being admitted to this office, he had to be cleared from any mistrust concerning his orthodoxy. His formal abjuration of messalianism and other heterodox teachings (preserved among Patr. Timotheos’s letters and published by Braun) opened the way to his consecration and (as far as we know) uneventful tenure as bp., enjoying the support of his patr.

This investigation should be seen in the context of the synod of 790/91, at which three mystics were condemned: Yoḥannan of Dalyatha, Yawsep Ḥazzaya, and (a certain) Yoḥannan Iḥidaya (the condemnation was later lifted under Timotheos’s successor). Since Nestorios had lived in the Monastery of Mar Yozadaq (in Beth Qardu), the home of Yoḥannan of Dalyatha, and also had known Yawsep Ḥazzaya, it is not surprising that he was associated with them.

In his ‘Book of Chastity’ Ishoʿdnaḥ of Baṣra attributes to Nestorios a no longer extant biography of Yawsep Ḥazzaya. Nestorios may have written it in defense of Yawsep when the latter became victim to accusations. One short treatise by Nestorios is preserved, ‘On the initial motion (mettziʿānutā) of God’s grace’. In it Nestorios argues that due to the ‘natural seeds’ that God instilled in us (weakened by sin but reinvigorated by Christ’s coming), we are able to receive God’s fire. He also maintains that man indeed is able to see God in a spiritual vision, a hotly debated question in Nestorios’s day. Nestorios certainly was ‘not a marginal’ figure in a period when the Ch. of E. was trying to strike a balance ‘between institution and prophecy’ (Berti).