All religious reality begins with the acceptance of the concrete situation as given one by the Giver, and it is this which Biblical religion calls the ‘fear of God.’ The ‘fear of God’ is the essence of ‘holy insecurity,’ for ‘it comes when our existence becomes incomprehensible and uncanny, when all security is shattered through the mystery.’ By ‘the mystery’ Buber does not mean the as yet undiscovered but the essentially unknowable -- ‘the undefinable and unfathomable,’ whose inscrutableness belongs to its very nature. The believing man who passes through this shattering of security returns to the everyday as the henceforth hallowed place in which he has to live with the mystery. ‘He steps forth directed and assigned to the concrete, contextual situations of his existence.’ This does not mean that he accepts everything that meets him as ‘God-given’ in its pure factuality.
He may, rather, declare the extremist enmity toward this happening and treat its ‘givenness’ as only intended to draw forth his own opposing force. But he will not remove himself from the concrete situation as it actually is.... Whether field of work or field of battle, he accepts the place in which he is placed. (Eclipse of God, ‘Religion and Philosophy,’ p. 50 ff.)
One should not willingly accept evil in one’s life but should will to penetrate the impure with the pure. The result may well be an interpenetration of both elements, but it may not be anticipated by saying ‘yes’ to the evil in advance. (From a conversation between Buber and Max Brod quoted in Max Brod, ‘Zur Problematik des Bösen und des Rituals,’ Der Jude, ‘Sonderheft zu Martin Bubers fünfzigstem Geburtstag,’ X, 5 [March 1928], ed. by Robert Weltsch, p. 109.)
Fear of God is the indispensable gate to the love of God. That love of God which does not comprehend fear is really idolatry, the adoration of a god whom one has constructed oneself. Such a god is easy enough to love, but it is not easy to love ‘the real God, who is, to begin with, dreadful and incomprehensible.’ (Eclipse of God, p. 50 f.; Martin Buber, Israel and Palestine, The History of an Idea [London: East & West Library; New York: Farrar, Straus & Young, 1952], p. 89.)
He who wishes to avoid passing through this gate, he who begins to provide himself with a comprehensible God, constructed thus and not otherwise, runs the risk of having to despair of God in view of the actualities of history and life, or of falling into inner falsehood. Only through the fear of God does man enter so deep into the love of God that he cannot again be cast out of it. (Israel and the World, ‘The Two Foci of the Jewish Soul,’ p. 31 f. Cf. ibid., ‘Imitatio Dei,’ p. 76 f.; For the Sake of Heaven, p. 46.)
The fear of God is only a gate, however, and not, as some theologians believe, a dwelling in which man can settle down. When man encounters the demonic, he must not rest in it but must penetrate behind it to find the meaning of his meeting with it. The fear of God must flow into the love of God and be comprehended by it before one is ready to endure in the face of God the whole reality of lived life. (Israel and the World, ‘The Two Foci of the Jewish Soul,’ p. 32; Eclipse of God, ‘Religion and Philosophy,’ p. 50 ff.; Two Types of Faith, pp. 137, 154.)