In chapter two of Luke, Luke names Quirinius as governor of Syria. It appears that the present state of knowledge about that man tells us that he didn't assume the position of governor of Syria until 6 AD. One article suggests a confusion of Quirinius' governorship of Syria and that of Galatia. How can this be brought into line with the death of Herod the Great in 4 BC? -- Christoph Widmer (Zurich)
The question you ask is a difficult one. Many solutions have been proposed:
It is possible Quirinius served two terms as governor, or even that he governed Syria earlier from the geographical location of his previous post. Interestingly, Tertullian (late 2nd century) places the nativity census in the governorship of Saturninus (9-3 BC).
Some suggest an alternate translation: "This registration [census] happened before Quirinius was governor of Syria." This is just possible, because 6 AD was a significant year, as Palestine reverted to direct Roman rule.
Perhaps Herod was finally obliged to order the census, and it was probably taken in the summer of the year 6 B.C., when Quirinius was a special Legatus Augusti to Syria, invested with the command of the army and entrusted with its foreign affairs, such as the relations between its several states and Rome, particularly where tension existed and military intervention might be necessary. Quirinius stood in exactly the same relation to Varus, the governor of Syria, as at a later time Vespasian did to Mucianus. Vespasian conducted the war in Palestine while Mucianus was governor of Syria and Vespasian was Legatus Augusti, holding precisely the same title and technical rank as Mucianus. This is an intriguing possibility, though speculative.
An error has crept into the text in the copying process, though the original wording was, presumably, correct.
I personally do not find any of these suggestions satisfying. Yet whatever our solution, we ought to take into account Luke's accuracy in things geographical and historical. There are some 200 terms that Luke uses—technical terms for government officials; names of cities, islands, and bodies of water; persons; etc—and as far as we know he never makes a mistake! Surely someone with such a high degree of credibility and proven accuracy should be trusted—assumed correct—unless there is truly no way of harmonizing what he wrote with other known facts.