And I, I will surely hide My face on that day… (Devarim 31:18).
The child crouches, weeping,
sheltered by the grey stone wall;
the Rebbe hears her sobbing
and gently asks her why.
She was playing hide-and-seek,
she says, and hid herself too well;
her friends despaired of finding her,
gave up and went away.
The Rebbe sighs and ponders,
hearing strains of God’s lament:
I hid My face, and now
My children search for Me no more.
This story is told of Rabbi Dov Ber (the Maggid) of Mezeritch* who was a disciple of the Baal Shem Tov. He perceived the child’s friends who gave up on her because she was so well-hidden, as a metaphor for God’s people who give up looking for Him and start to live their lives without Him. And God is pained when they no longer seek Him out.
Rabbi Abraham Joshua Heschel** was one of the leading Jewish theologians and Jewish philosophers of the 20th century. Much of his work sought to free Jewish theology from the constraints of Maimonides’ philosophical concept of an absolutely transcendent God who is independent of humanity. Rabbi Heschel counterposed the concept of divine pathos, that is, of a God who searches for man, who is in need of man. He emphasized the interdependency of the divine and the human. He held that Judaism is so commandment-oriented precisely because God’s kingship is realized on earth through the fulfillment of the commandments. He noted the striking rabbinical concept that it is human witness that makes God real, often citing the midrashic gloss to Isaiah 43:12, ” ‘So you are My witnesses,’ declares the Lord, ‘and I am God,’ meaning: “When you are my witnesses, then I am God, but when you are not my witnesses, then I am, as it were, not God.” 
Based on the phrase, “Va’anochi haster asteer panai – And I, I will surely hide My face on that day,” the Ba’al Shem Tov teaches that the repetition of the word “I” means that even in the hardest times of (God’s) concealment, the “Anochi – I” will still be there. That, he says, is God’s promise, that He will not desert us in times of trouble.
The Chiddushei HaRim teaches on the same phrase, that if we know and feel that there is hiddenness, it is not really hiddenness. The tragedy, he says, is not so great, because then come the longings and yearnings to reveal the Shechina – the Divine Presence. These break through all barriers – and there is no greater repentance than this. However, he says, “The trouble is when the hiddenness is itself hidden, and we do not even realise that God’s face is hidden. No-one looks for God, and for His supreme loving-kindness and for heavenly radiance.” The Chiddushei HaRim interprets this phrase as “I will hide the hiddenness (from them),” meaning “I will dull their hearts and blunt their senses so they will not even feel that they are missing the yearning for God.”
The Etz Hayyim commentary of the JPS, says on the concept of God concealing His face, “To understand the Shoah, Martin Buber,*** who fled Germany for Palestine when the Nazis came to power, fastened on this image of God’s hiding. God is always present, but sometimes turns aside and hides the Divine countenance. Terrible things happen when God’s countenance is hidden, when God’s attention is turned away.”
 Excerpted from First Things, the theology of Abraham Joshua Heschel by Reuven Kimelman. http://www.firstthings.com/article/2009/12/the-theology-of-abraham-joshua-heschel
*Rabbi Dov Ber ben Avraham of Mezeritch (1700/1704/1710 – 1772) was a disciple of Rabbi Yisrael Baal Shem Tov, the founder of Chassidic Judaism, and was chosen as his successor to lead the early movement. Rabbi Dov Ber is regarded as the first systematic exponent of the mystical philosophy underlying the teachings of the Baal Shem Tov, and through his teaching and leadership, the main architect of the movement. He established his base in Mezeritch (in Volynia), which moved the center of Chassidism from the Baal Shem Tov’s Medzhybizh (in Podolia), where he focused his attention on raising a close circle of great disciples to spread the movement. His inner circle of disciples, known as the Chevraia Kadisha (“Holy Brotherhood”), included his son Rabbi Avraham HaMalach (The Angel), Rabbi Nachum of Czernobyl, Rabbi Elimelech of Lizhensk, Rabbi Zusha of Hanipol, Rabbi Levi Yitzchak of Berditchev, Rabbi Baruch of Medzhybizh, Rabbi Aharon (HaGadol) of Karlin, Rabbi Menachem Mendel of Vitebsk, Rabbi Shmuel Shmelke of Nikolsburg and Rabbi Shneur Zalman of Liadi. These disciples, being themselves great Talmudic authorities and well-versed in Kabbalah and Chassidic philosophy, were successful in turning Chassidut into a vast movement. After R’ Dov Ber’s death, avoiding the unified leadership of the first two generations, this third generation of leadership took their different interpretations and disseminated across appointed regions of Eastern Europe. Under the inspiration of their teacher, this rapidly spread Chassidism beyond the Ukraine, to Poland, Galicia and Russia.
His teachings appear in his own books and in the works authored by his disciples.
**Rabbi Abraham Joshua Heschel (1907 – 1972) was a Polish-born American rabbi and one of the leading Jewish theologians and Jewish philosophers of the 20th century. He was descended from preeminent European rabbis on both sides of his family. After a traditional yeshiva education and studying for Orthodox rabbinical ordination semicha, Rabbi Heschel pursued both a doctorate at the University of Berlin and a liberal rabbinic ordination, studying under some of the most eminent Jewish educators of the time. He joined a Yiddish poetry group and in 1933, published a volume of Yiddish poems. In late October 1938, while living in a rented room in the home of a Jewish family in Frankfurt, he was arrested by the Gestapo and deported to Poland. He spent ten months lecturing on Jewish philosophy and Torah at Warsaw’s Institute for Jewish Studies. Six weeks before the German invasion of Poland, he left Warsaw for London. His mother and three of his five siblings were murdered by the Nazis (his father had died when Heschel was nine). He reached New York City in 1940 and in 1946 took a position at the Jewish Theological Seminary of America (JTS) in New York City, the main seminary of Conservative Judaism. He served as professor of Jewish Ethics and Mysticism until his death.
Heschel explicated many facets of Jewish thought, including studies on medieval Jewish philosophy, Kabbalah, and Chassidism. According to some scholars, he was more interested in spirituality than in critical text study.
Heschel believed the teachings of the Hebrew prophets were a clarion call for social action in the United States and worked for African Americans’ civil rights and against the Vietnam War.
Heschel is a widely read Jewish theologian whose most influential works include Man Is Not Alone, God in Search of Man, The Sabbath, and The Prophets. At the Vatican Council II, as representative of American Jews, Heschel persuaded the Roman Catholic Church to eliminate or modify passages in its liturgy that demeaned the Jews, or referred to an expected conversion to Christianity. His theological works argued that religious experience is a fundamentally human impulse, not just a Jewish one. He believed that no religious community could claim a monopoly on religious truth.
***Martin Buber (1878 – 1965) was an Austrian-born Israeli Jewish philosopher best known for his philosophy of dialogue, a form of existentialism centered on the distinction between the I–Thou relationship and the I–It relationship. Born in Vienna, Buber came from a family of observant Jews (he was a direct descendant of the prominent 16th century rabbi, R’ Meir Katzenellenbogen, known as the Maharam of Padua) but he broke with Jewish custom after a personal religious crisis: he then started reading Kant, Kierkegaard, Nietzsche. The latter two, in particular, inspired him to pursue studies in philosophy. In 1896, Buber went to Vienna to pursue secular studies in philosophy. In 1902, he became the editor of the weekly Die Welt, the central organ of the Zionist movement, although he later withdrew from organizational work in Zionism. In 1923, Buber wrote his famous essay on existence, Ich und Du (later translated into English as I and Thou), and in 1925, he began translating the Hebrew Bible into the German language.
In 1930, Buber became an honorary professor at the University of Frankfurt am Main, but resigned in protest from his professorship immediately after Adolf Hitler came to power in 1933. He then founded the Central Office for Jewish Adult Education, which became an increasingly important body as the German government forbade Jews to attend public education. In 1938, Buber left Germany and settled in Jerusalem, receiving a professorship at Hebrew University and lecturing in anthropology and introductory sociology.