After the appearance of the first volume of The History of Dogma, Theodosius Harnack wrote to his son in Marburg: “Our difference is not theological, but rather one which is profoundly and directly Christian…. He who views the resurrection as you do, is in my view no longer a Christian theologian.”
“Superseded but never surpassed, Harnack’s work remains, after more than eighty years, the one interpretation of early Christian doctrine with which every other scholar in the field must contend”. Pelikan, Jaroslav The Christian Tradition vol. 1 (Chicago, 1971) p.359.
Dietrich Bonhoeffer‘s (1906-1945) tribute to his mentor, Harnack: “That I was his student for a time is but a passing thing, that I am his pupil remains always.”
As the Director-General of Berlin’s Royal Library, 1906–21 (re-named the Prussian State Library in 1919), Harnack insisted upon the circulation of books outside of the library when that procedure was questioned by German libraries. Libraries are “neither museums nor cabinets of curiosities; that their function was not so much to conserve books as to put them to use, and that the best adornment of a library was a book worn in service.”
Hirsch, Felix E. “The Scholar as Librarian: To the Memory of Adolf von Harnack,” The Library Quarterly 9 (July, 1939) 3:299-320
A contemporary Roman theologian, Alfred Loisy, who criticized (IMHO bested) Harnack over the later’s Marcionism, understanding of the development & function of doctrine & tradition, etc., once made the trenchant observation: “Jesus annoncait le royaume, et c’est l’Eglise qui est venue” – loosely translated: “Jesus expected the kingdom of God, & instead He got the church”. (L’Evangile et l’Eglise, 5th ed., 1929, p.153) Such remarks (plus a little modernism) got Loisy excommunicated, & ironically, it was a quote which came to represent the position of Harnack himself!