AZR grew up in a Chabad home in Lyady, went through a period of estrangement, and upon his immigration to Jaffa (1905/6) and his settling near the home of Rav Kook, he returned to a strictly observant way of life. In his own words:
"I felt that changes were taking place within me, that my spirit was being renewed within me. Our teacher Rav Kook had a great influence upon me. I loved to hear his sharp sermons, and I kept his deep and clever aphorisms in my heart. His style, too, made a powerful impression on me." AZR, quoted by Moshe Nachmani, "Mechaber Olamot" (Uniter of Worlds) (hakibbutz.org.il). See also "AZR and Rav Kook" and "The Excommunication Affair in Safed".
AZR sought to bring Rav Kook together with the young writers of Neve Tzedek. According to the source, he brought to the Rav S.Y. Agnon and the poet Yosef Tzvi Rimon, who became his disciples and admirers; he even tried to draw Brenner closer (but that "was too difficult"). A photograph from 1910 is documented: AZR (wearing a hat), Brenner, Agnon and Shimoni in Neve Tzedek.
He also edited the writings of Rav Kook (detailed in "AZR and Rav Kook"): "Ein Ayah" and its indexes (in the Genazim archive), the essay "On the Course of Ideas in Israel", and he took part in editing the poem "Whisper to Me a Secret, All of Existence". In 5671 (1911) he published "Keter Torah", the first biography of Rav Kook. Secondary source
A less familiar documented finding: even before the labor movement arose, AZR was an official member, and indeed a committee member, of the "Mizrachi" movement in Jaffa:
"At the last assembly, held on the night of Hoshana Rabbah, a permanent committee was elected [for the 'Mizrachi' branch in Jaffa]. Among the committee members: A. Z. Rabinovitz." The newspaper "HaHerut" (on behalf of the Mizrachi center in the Holy Land), 25 Tishrei 5670 [1909], as quoted by Nachmani. Press document
This detail expresses his religious-national spirit, and rounds out his portrait as someone who moved naturally between circles. AZR was also one of the leaders of the "Israelite Culture" (HaTarbut HaYisraelit) society in Jaffa, which operated under the presidency of Rav Kook (together with R. Zerach Barnett, R. Sh. T. Gefen, R. Tzvi Yehuda Kook, Y. Tz. Rimon), and one of the editors of its booklet.
Of AZR, who at the age of 75 received membership card number 1 in the Histadrut yet remained an observant Jew, Chaim Bograshov wrote this apt phrasing:
"AZR is perhaps the only one among us who 'bridges from one extreme to the other'. He is the beloved Hasid, close to Rav Kook, and together with that a member and grandfather of the labor federation in this land, without any concessions or doubts to one side or the other." Chaim Bograshov on AZR, quoted by Nachmani. (Compare "AZR and the Labor Movement".)
In this spirit AZR also brought to the workers' audience "a beautiful teaching from R. Nachman of Bratslav", and his aspiration was "to see religious people within the labor movement".