What does Luke 1:18 mean?
Zechariah and his wife, Elizabeth, are getting older and have never had children. Even—or especially—for godly, righteous people, this would have been a difficult experience (Luke 1:5–7). Zechariah is a priest, chosen to offer incense in the temple on a particular day (Luke 1:8–10). While alone in the room containing the altar, he has seen an angel, who predicts that the couple's request will be answered: Elizabeth will have a son (Luke 1:11–13). Further, that son will play an important role in fulfilling prophecy (Luke 1:14–17; Malachi 3:1; 4:5–6).It would be natural to wonder at such a miraculous statement, even in the presence of an angel. There would be many questions about how such a thing would happen. Wondering "in what way" is how Mary, given even more miraculous news, will respond (Luke 1:34). Zechariah's response here seems more about "if," rather than "how." The NASB clarifies this by including the phrase "how can I know this for certain?"
It's that tinge of doubt—doubt that this event really will occur—which earns Zechariah a relatively mild rebuke from the angel (Luke 1:19–20).
Luke 1:5–25 explains how Elizabeth, the childless wife of a priest, learns that she will give birth to a prophet. This child will eventually be known as John the Baptist. Her husband, Zechariah, learns this from an angel but doubts due to his advanced age. As a result, he is rendered temporarily mute, and likely deaf as well (Luke 1:62). As predicted, he and Elizabeth conceive and await the birth of their son. This occurs several months before Elizabeth's relative, Mary, receives even more amazing news from an angel.
The angel Gabriel predicts two miraculous births. The first is a son born to Zechariah and Elizabeth: an older, childless priest and his wife. Because Zechariah initially doubts this message, he is temporarily made unable to speak. Their child will be known as John the Baptist, a powerful herald of the Messiah. The Promised One whom John will proclaim is the second birth predicted by Gabriel. He tells an engaged virgin, Mary, that God will miraculously conceive His Son in her. The two women meet and rejoice over their blessings. John's arrival sets the stage for Luke's familiar account of the birth of Jesus Christ.
