The root of all sin is fear: the very deep fear that we are nothing; the compulsion, therefore, to make something of ourselves, to construct a self-flattering image of ourselves we can worship, to believe in ourselves - our fantasy selves. I think all sins are failures in being realistic; even the simple everyday sins of the flesh, that seem to come from mere childish greed for pleasure, have their deepest origin in anxiety about whether we really matter, the anxiety that makes us desperate for self-reassurance. To sin is always to construct an illusory self that we can admire, instead of the real self we can only love.
As Luther said, sin is being curved in on the self, to be self-regarding. Oswald Bayer's book, Living by Faith, masterfully addresses these issues. He opens by discussing the "battle for mutual recognition". We are compelled to justify ourselves and our behavior, to give account of ourselves: Who am I? What is my story? Why did I do what I did? If we are never addressed in this way we become socially non-existent. The individual is formed in this nexus of interaction:
Striving to find approval in the eyes of others, being noticed and not being dismissed as nothing by others, demonstrates that I cannot relate to myself without relating to the world. It applies to our social birth as well as our physical birth. I constantly vacillate, even to the very end of life, between the judgment others make about me and my own judgment of myself. I am constantly trying to ascertain others' judgment about me and my own judgment of myself; I arrive at some point of calm, and then become unsure of myself again. My identity is a floating one. Who am I? asked Dietrich Bonhoeffer. Am I what others say about me? Am I what I know about myself? Am I balanced between these different evaluations? Questions such as these relate to my inner being, not just something external.
This inward focus is a source of anxiety about the self, which, as McCabe says, is a source of sin. Jesus said that the law is summed up in the dual commandment, "Love God with all your heart and your neighbor as yourself". That requires looking outside of yourself, to God and your neighbor. Justification by faith in God's promise is what enables us to do this. Bayer continues:
Those who are born anew are no longer entangled with themselves. They are solidly freed from this entanglement, from the self-reflection that always seeks what belongs to itself. This is not a deadening of self. It does not flee from thought and responsibility. No, it is the gift of self-forgetfulness. The passive righteousness of faith tells us: You do not concern yourself at all! In that God does what is decisive in us, we may live outside ourselves and solely in him. Thus, we are hidden from ourselves, and removed from the judgment of others or the judgment of ourselves about ourselves as a final judgment. "Who am I?" Such self-reflection never finds peace in itself. Resolution comes only in the prayer to which Bonhoeffer surrendered it and in which he was content to leave it. "Who am I? Thou knowest me. I am thine, O God!"
If sin is being curved in on the self then justification is having your spine straightened so that you can look outward to God and your neighbor. It should be clear, then, that the doctrine of justification by faith is the opposite of the idea that the only thing that matters is the relationship with God. Justification is not a simple "getting right with God" so that we can be prepared to get out of this world and into heaven. Justification sets us in a new relationship with God and the world. It creates, as Bayer says, "a new worldliness". The justified person can leave behind anxiety about the self, because the old self has been drowned in baptismal waters and a new, un-self-regarding self has been created. We are set free to serve others.