From Karl Barth, The Epistle to the Romans, at page 98:
The vision of the New Day remains an indirect vision; in Jesus revelation is a paradox, however objective and universal it may be. That the promises of the faithfulness of God have been fulfilled in Jesus the Christ is not, and never will be, a self-evident truth, since in Him it appears in its final hiddennesss and its most profound secrecy. The truth, in fact, can never be self-evident, because it is a matter neither of historical nor of psychological experience, and because it is neither a cosmic happening within the natural order, nor even the most supreme event of our imaginings. Therefore it is not accessible to our perception; it can neither be dug out of what is unconsciously within us, nor apprehended by devout contemplation, nor made known by the manipulation of occult psychic powers. These exercises, indeed, render it the more inaccessible. It can neither be taught nor handed down by tradition, nor is it a subject of research. Were it capable of such treatment, it would not be universally significant, it would not be the righteousness of God for the whole world, salvation for all men. . . .For all faith is both simple and difficult; for all alike it is a scandal, a hazard, a Nevertheless ; to all it presents the same embarrassment and the same promise; for all it is a leap into the void. And it is possible for all, only because for all it is equally impossible.