"Have the men of our time still a feeling of the meaning of sin? Do they, and @@do we, still realize that sin does not mean an immoral act@@, that "sin" should never be used in the plural, and that not our sins, but rather our sin is the great, all-pervading problem of our life? Do we still know that it is arrogant and erroneous to divide men by calling some "sinners" and others "righteous"? For by way of such a division, we can usually discover that we ourselves do not quite belong to the "sinners", since we have avoided heavy sins, have made some progress in the control of this or that sin, and have been even humble enough not to call ourselves "righteous". Are we still able to realize that this kind of thinking and feeling about sin is far removed from what the great religious tradition, both within and outside the Bible, has meant when it speaks of sin?"
"I should like to suggest another word to you, not as a substitute for the word "sin", but as a useful clue in the interpretation of the word "sin", "separation" . Separation is an aspect of the experience of everyone. Perhaps the word "sin" has the same root as the word "asunder". In any case, sin is separation. To be in the state of sin is to be in the state of separation. And separation is threefold: there is separation among individual lives, separation of a man from himself, and separation of all men from the Ground of Being. This three-fold separation constitutes the state of everything that exists; it is a universal fact; it is the fate of every life. And it is our human fate in a very special sense. For we as men know that we are separated. We not only suffer with all other creatures because of the self-destructive consequences of our separation, but also know why we suffer. We know that we are estranged from something to which we really belong, and with which we should be united. We know that the fate of separation is not merely a natural event like a flash of sudden lightning, but that it is an experience in which we actively participate, in which our whole personality is involved, and that, as fate, it is also guilt. Separation which is fate and guilt constitutes the meaning of the word "sin". It is this which is the state of our entire existence, from its very beginning to its very end. Such separation is prepared in the mother's womb, and before that time, in every preceding generation. It is manifest in the special actions of our conscious life. It reaches beyond our graves into all the succeeding generations. It is our existence itself. Existence is separation! Before sin is an act, it is a state."
The Shaking of the Foundations by Paul Tillich - Chapter 19: You Are Accepted