In a letter to Karl Barth, Emil Brunner wrote the following concerning his struggle in faith (the original is in German, therefore the numerous brackets, etc.):
This is my experience: Either I will completely be at the center...: God lives, let God matter. But then I soon find that all I have in my hands are four letters [G-O-T-T]..., an abstract thought, with which I can neither understand nor master my life. I can say, Let God matter. But, in reality, what matters is not God but my thought that "God should matter."... Or, on the other hand, depressed from this experience, I... fall into the other extreme: "God should matter" [becomes] "The Good should matter," [faith mixed up with] a moral-cultural lifestyle, a system of ethics, that, up to a certain point, shines through one's life, but naturally (as little as "the law" in Paul) has no power...I've always had the feeling - and my moral experiences confirm it - that I have still not yet penetrated to God, that my faith has produced nothing.This quote was taken from the book "For the sake of the world" (see my library in the sidebar).
Barth later responded with the formulation "God is God and God is God". Food for deep thought.