It is entirely obvious, as it seems to us, that the finite never can comprehend the Infinite; and perhaps we may go further and say, that it never can make any real, any assignable approximation to it. Let it be supposed, that God manifests himself to the full extent of the capacity, which the creature possesses to receive the manifestation, it is still a manifestation only so far as the creature is able to receive it. It is only a SIGN of God, a mark, an indication; but not really and truly the thing signified. There are still heights and depths beyond. We admit, that it is a manifestation of that which a finite creature can comprehend; but it is not a manifestation, and never can be, of that, which is above comprehension, of the ALL in ALL.
We say, therefore, that there is, and can be no manifestation, which either does or can exclude the principles and the applications of FAITH. Out of the limits of the Trinity, beyond the pale of that intercommunion which exists in the persons of the Godhead itself, all holy beings, whatever their rank and whatever name they bear, live in the same manner. Faith is as truly necessary to the inward life of an Angel or of a Seraph, as it is to that of a redeemed sinner here on earth. They see further, it is true; and it is probably the case that the manifestation of God corresponds to the increased length and breadth of their vision; but beyond their power of sight and of all present knowledge, enlarged and bright as it is, there is still a region undiscovered, a vast land unknown. A land, where even angelic minds have never traveled, and which can be reached and explored only by faith.
When we take the view of the subject, which has now been given, no language can express the value, which we should attach to this wonderful principle; it being impossible, in the nature of things, for God so to manifest himself as to exclude its necessity and importance. And we may add, if all beings, angels as well as men, must live in this way, must live by faith alone, must live so now and live so forever, then it is hazardous to desire any other method of living. Satan understood the nature and tendency of such desires, when, in support of his fatal proposition to Eve, he said, “your eyes shall be opened, and ye shall be as gods, knowing good and evil.” Be content, then, to acknowledge, that there are some things in God, which the human mind never can fully know. And this being the case, be willing to live by believing; and neither think nor desire to live in any other way. Be willing to see every outward light extinguished, to see the eclipse of every star in the blue heavens, leaving nothing but darkness and perils around, if God will only leave in the soul the inner radiance, the pure bright lamp which faith has kindled.
— edited from The Life of Faith (1852) Part 2, Chapter 1.