How does the proposed Q source relate to the Synoptic Gospels?

In the context of literary criticism and the study of biblical literature, the hypothetical Q source (from the German Quelle, meaning "source") is a central component of the two-source hypothesis used to explain the relationships between the Synoptic Gospels—Matthew, Mark, and Luke.12

Scholars propose that while the authors of Matthew and Luke relied on the Gospel According to Mark for their narrative framework, they also drew from Q to account for a significant body of shared material—primarily logia (sayings of Jesus)—that is absent from Mark. Because this shared material often appears verbatim in Matthew and Luke but is placed in different contexts or sequences, researchers suggest that the authors of these Gospels independently incorporated and adapted Q to suit their specific theological goals and audiences.12

Although no physical copy of Q has been discovered, its existence is inferred through intensive textual analysis of the structural and linguistic parallels between the Synoptic Gospels.13