Consequently most researchers would concur with a stratification of the surviving text into at least three distinct layers of composition:* an editorial layer dating from the late 16th century; and comprising, at the least, the Spanish preface and the Arabic annotations,* a layer of vernacular narrative composition, either in Spanish or Italian, and dating from no earlier than the mid-14th century,* a layer derived from earlier source materials, almost certainly transmitted to the vernacular author/translator in Latin; and comprising, at the least, those extensive passages in the Gospel of Barnabas that closely parallel pericopes in the canonical gospels; but whose underlying text appears markedly distinct from that of the late medieval Latin Vulgate (as for instance in the alternative version of the Lord's Prayer in chapter 37, which includes a concluding doxology, contrary to the Vulgate text, but in accordance with the Diatessaron and many other early variant traditions);Much of the controversy and dispute concerning the authenticity of the Gospel of Barnabas can be re-expressed as debating whether specific highly transgressive themes (from an orthodox Christian perspective) might already have been present in the source materials utilised by a 14th–16th-century vernacular author, whether they might be due to that author himself, or whether they might even have been interpolated by the subsequent editor.