Short answer: Evangelical Christians overwhelmingly identify the author of Luke 2:6–7 as Luke the physician, the same Luke who wrote the Gospel of Luke and the Book of Acts.

Why Luke is identified as the author (evangelical perspective)
– Internal biblical evidence: The Gospel itself is addressed to “Theophilus” and begins with a preface describing careful investigation (Luke 1:1–4). Acts, which continues the story, is traditionally linked to the same author.
– New Testament testimony: Paul’s letters mention a “Luke, the beloved physician” (Colossians 4:14) and list Luke among Paul’s companions (Philemon 24; 2 Timothy 4:11). The “we” sections in Acts (Acts 16; 20; 27–28) are understood by many evangelicals as indicating the presence of the author with Paul on some journeys—supporting Lucan authorship of both books.
– Early church tradition: From the second century onward church fathers (e.g., Irenaeus, Tertullian) attributed the third Gospel and Acts to Luke, a companion of Paul.

Who Luke was (as understood by evangelicals)
– A Gentile or Hellenistic Christian: Many evangelicals hold that Luke was not a Palestinian Jew but a Gentile or Hellenist, explaining his polished Greek style and interest in explaining Jewish customs for a broader audience.
– A physician and educated writer: Referred to as a “physician” in Colossians, Luke’s writing is noted for good Greek, careful chronology, and attention to detail.
– Paul’s traveling companion: He likely traveled with Paul for parts of Paul’s ministry and may have been with him in Rome, which helps date Luke–Acts to around the time of Paul’s imprisonment (commonly placed by evangelicals in the 50s–60s AD for composition of Luke–Acts).

Why evangelicals trust this authorship and Luke’s account of Jesus’ birth
– Investigative historian: Luke 1:1–4 claims the author researched eyewitness testimony and written sources to produce an “orderly account.” Evangelicals take this as a claim to careful historical inquiry.
– Literary and historical detail: Luke includes specific names, places, and historical markers (e.g., census, governors) and presents coherent narrative links between his Gospel and Acts, supporting the view of an informed, reliable author.
– Theological emphases consistent with Luke: Attention to the marginalized (Mary, shepherds), joy and praise, fulfillment of prophecy, and the role of the Holy Spirit are hallmarks of Luke’s theology and appear clearly in the nativity narrative (including Luke 2:6–7).

Practical implications for Luke 2:6–7
– Evangelicals typically treat Luke 2:6–7 as part of an eyewitness-informed, historically trustworthy account of Jesus’ birth written by Luke for Theophilus and the early church.
– Many evangelicals also suggest Luke may have used direct testimony from Mary and other eyewitnesses when composing the birth narratives (cf. Luke 1:1–4), which helps explain the intimate, human details in verses like 2:6–7.

If you’d like, I can summarize the internal evidence Luke cites, outline the early patristic testimony for Lucan authorship, or show how Luke’s style and emphases compare with the other Gospels.