The prologue to the Gospel of Luke specifies that many attempted to write an “account” of what Jesus accomplished in bringing about the fulfillment of salvation history (Luke 1:1). Papias of Hierapolis insists that he preferred to learn about Jesus from a living voice rather than from books (in Eusebius, Ecclesiastical History 3.39.4). The Apostle Paul preached a sermon where he quoted Jesus as saying that “it is more blessed to give than to receive” (Acts 20:35), even though this line is not found in any of the New Testament Gospels. Ignatius of Antioch reassured the Smyrneans that the resurrected Christ was not a “bodiless demon” (Smyrn. 3.2), a quote that sounds like Luke 24:39, but that later church authorities ascribed to other apocryphal Christian sources (cf. Origen, princ. praef. 8; Eusebius, h. e. 3.36.11; Jerome, Vir. ill. 16; Is. praef. 18). These examples can be multiplied to demonstrate that there were oral and written sources about Jesus that preceded the composition of the New Testament Gospels and that continued well after these Gospels were published. This raises the question of how scholars determine when an ancient Christian writer was referencing one of our New Testament Gospels or was referring to a saying or deed of Jesus that parallels material found in the New Testament Gospels but actually derived from another (extant or lost) Christian writing or oral tradition.
Scholars have thus developed methods for detecting intertextual references or allusions to the Gospels in later Christian literature. The clearest cases are when a Christian writer uses a citation formula, such as “it is written in the Gospel according to Matthew” or even “the Lord says in the gospel.” If this is not present, some scholars allow for literary dependence on a Gospel if there is enough verbal and thematic agreement with that Gospel and possible parallels to other texts are more distant. They might also look for rare terminology or unique material from the Gospel that is reproduced in the later text or explain the differences in wording or content as reflecting a writer’s purposeful alterations to a source text rather than two independent writers drawing on a shared tradition. The other approach originally developed by Helmut Koester is to argue that literary dependence can only be demonstrated when a later Christian writer reproduces an earlier Gospel writer’s redactional contributions. For instance, we might be able to detect when Matthew’s or Luke’s deliberate editorial changes to Mark’s text have influenced a subsequent Christian writer. I offer an example of this method in my article “Why Did the Gospel of Mark Survive?”, which is based on pages 230-36 of my book The Gospel on the Margins: The Reception of Mark in the Second Century (Minneapolis: Fortress, 2015). Here are some specialist studies on this topic:
- Gregory, Andrew, and Christopher M. Tuckett. Editors. The Reception of the New Testament in the Apostolic Fathers. Oxford: Oxford University Press, 2005.
- Gregory, Andrew. The Reception of the New Testament in the Apostolic Fathers. Oxford: Oxford University Press, 2005.
- Hill, Charles E. The Johannine Corpus in the Early Church. Oxford: Oxford University Press, 2004.
- Massaux, Édouard. The Influence of the Gospel of Saint Matthew on Christian Literature Before Saint Irenaeus. 3 vols. Translated by Norman Belval and Suzanne Hecht. Edited by A. J. Bellinzoni. Macon, GA: Mercer University press, 1990.
- Koester, Helmut. Synoptische Überlieferung beiden Apostolischen Vätern. TU 65. Bd. Berlin: Akademie-Verlag, 1957.
- Koester, Helmut. “Written Gospels or Oral Tradition?” JBL 113.2 (1994): 293-97.
- Köhler, Wolf-Dieter. Die Rezeption des Matthäusevangeliums in der Zeit vor Irenäus. Tübingen: Mohr Siebeck, 1987.
- Nagel, Titus. Die Rezeption des Johannesevangeliums im 2. Jahrhundert: Studien zur vorirenäischen Auslegung des vierten Evangeliums in christlicher und christlich-gnostischer Literatur. Arbeiten zur Bibel und ihrer Geschichte 2. leipzig: evangelische verlagsanstalt, 2000.
- Tuckett, Christopher. Nag Hammadi and the Gospel Tradition: Synoptic Tradition in the Nag Hammadi Library. Edinburgh: T&T Clark, 1986.
- Wenham, David. Gospel Perspectives, Volume 5: The Jesus Tradition Outside of the Gospels. Sheffield: JSOT Press, 1984.
- Young, Stephen E. Jesus Tradition in the Apostolic Fathers: Their Explicit Appeals to the Words of Jesus in Light of Orality Studies. WUNT 2.311. Tübingen: Mohr Siebeck, 2011.