Final answer:
Luke includes the poetic speeches of John the Baptist and Jesus' parents to provide a narrative that integrates the supernatural with its historical context, fulfill prophetic themes in Christian theology, and weave Christian stories into the broader cultural and religious motifs.
Step-by-step explanation:
Luke includes the poems which John the Baptist and Jesus' parents speak to fulfill literary and theological purposes. These poetic sections, similar to other Greco-Roman biographical works, provide a rich, textured narrative that helps to weave the supernatural with the historical context. Additionally, such poems are meant to highlight key prophetic and redemptive themes that are significant in Christian theology.
For instance, the inclusion of these passages aligns with the motif of the golden age prophesied after the unrest of the Late Republic, resembling pastoral poems that foresaw societal renewal through the birth of a remarkable child. However, the identity of the child in Luke's context is clearly Jesus, distinguishing it from other interpretations of the time that might have pointed to a child of Mark Antony and Octavia.
The portrayal of scenes such as The Baptism of Christ draws from earlier Classical models and artistic representations which imbue the narrative with layers of cultural and symbolic meaning. Moreover, the artistic representations like the muscular man symbolizing the river in the baptism of Jesus allude to pre-existing iconography, thereby integrating the Christian story into the broader tapestry of cultural and religious motifs.