The Bearing of Recent Discovery on the Trustworthiness of the New Testament (1915) page 235
"The truth of the historical surroundings in which Luke's narrative places the birth of Jesus does not prove the supreme facts, which give human and divine value to the birth are true."
and
page 89
"You may press the words of Luke in a degree beyond any other historian’s, and they stand the keenest scrutiny and the hardest treatment, provided always that the critic knows the subject and does not go beyond the limits of science and of justice"
and
Page 254
"We know that Luke was right in the external facts, because the records have disclosed the whole system of the census ; but as to the inner facts, the birth and the divine nature of Jesus, there can (as said above) be no historical reasoning, for those are a matter of faith, of intuition, and of the individual human being's experience and inner life."
and page 236
The surrounding facts are matter of history, and can be discussed and proved by historical evidence. The essential facts of the narrative are not susceptible of discussion on historical principles, and do not condescend to be tested by historical evidence