What does Luke 2:3 mean?

This passage establishes a time frame for Jesus' birth, based on political events in the Roman Empire. Luke ties in two names. The first is Augustus, an emperor who ruled from 27 BC to 14 AD (Luke 2:1). The other is Quirinius, who governed Syria during part of that same period (Luke 2:2). The reference to Quirinius is less clear, so scholars are not in complete agreement on what dates Luke means in his second comment.

The driving event in this section is an order for the entire Roman Empire to be counted. To participate in this census, it seems, some people were required to arrive in their ancestral hometowns. In Joseph's case, this is Bethlehem (Luke 2:4). He takes along Mary, who is engaged to be his wife (Luke 1:26–27) and pregnant via the Holy Spirit (Luke 1:30–33; 2:5). This will provide further opportunity to fulfill prophecy (Micah 5:2).

As many people were travelling into the area, lodgings are crowded. This is why Mary, after giving birth to Jesus, will find herself using a feeding trough as a cradle (Luke 2:7).