The single most important source detectable behind the oeuvre of Cynewulf is, unsurprisingly, the Bible, echoes of various parts of which are scattered throughout three of his four poems. Cynewulf's version of the Passio of St Juliana is nearest in all particulars to that which appears in an early ninth-century collection of Latin saints' lives now in Paris. The role of the Anglo-Saxon poet as editor and arranger, rather than as simple translator of his Latin material, is clearly demonstrated than in Cynewulf's handling of his sources for Fates of the Apostles. If three of his poems reveal a debt to hagiography, the fourth, Christ II, signals Cynewulf's knowledge of certain writings of the Fathers of the church. Cynewulf's corpus shows that he could handle the forms of vernacular poetry. As he had access to selected works by Gregory, Ambrose and Bede, it implies that the poet was based at a major ecclesiastical centre.

There were two languages in extensive use for writing and reading in Anglo-Saxon England: Latin and English. It is convenient to distinguish between literacy in Latin and literacy in English. At the time of the conversion, Latin was an entirely foreign language to the English, who had had relatively little contact with the Roman Empire or with Latin-speaking Britons. Competence and indeed skill in reading and writing Latin came remarkably quickly to the English after conversion. Within seventy years Aldhelm was composing highly sophisticated Latin verse and prose. Ælfric's vernacular works are explicitly addressed to the laity or the secular clergy, while his Latin writings are for monks. Byrhtferth of Ramsey makes the distinction explicit in his Enchiridion. The production of documents in the vernacular seems to have begun very soon after the conversion. From King Alfred's time onwards the vernacular is in regular use for books of Bible translations, homilies, saints' lives, history, computus, medicine and much else.