Sometimes, sin to be an anachronistic concept lacking meaning and relevance in the twenty-first century. However, in thinking about human existence, I find the concept of sin meaningful in two different ways.
First, if ethics are at least partially rooted in reciprocal altruism, as I believe they are (cf. Ethical Musings Naturalistic ethics and Discerning a basis for human rights and dignity), then sin may usefully connote some or all behavior rooted in self-centeredness. In this sense, the reality of sin emphasizes that not all behaviors contribute to human flourishing.
Reciprocal altruism denotes behaviors in which a person acts to benefit her/his self by aiding others, expecting that the payback may come directly from those aided but is more likely to come from others. Reciprocal altruism probably began among the primates, who first banded together 52 million years ago, discovering about 16 million years ago that aiding one’s extended family improved one’s quality of life. (Nick Bascom, “Two Steps To Primate Social Living,” Science News, November 9, 2011) In time, this recognition expanded to include the clan, tribe, and, in most parts of the world, the nation. A gradually increasing number of people recognize that their quality of life depends upon not only the national community but also the global community.
At least some self-centered behavior intended to benefit the individual at the expense of others is thus an unfortunate evolutionary legacy, a function of the incomplete development of reciprocal altruism. To the extent that self-centered behaviors are not autonomous, sin is partially a function of inheritance rather than choice. This coheres well with the traditional theological understanding of original sin, sin passed from one generation to the next through no fault of the present generation.
Second, sin is an unfortunate but inescapable consequence of human finitude.
The person who thinks he can move beyond his self only lives in a dream world. Wherever he might move, he brings his self with him. A person does not escape his self either through diversion or through asceticism. To be sure, that is not even worth striving for. l the wish to escape one’s self is only a short circuit in the whole enterprise. Aversion to one’s self is ingratitude. A person can overcome his self-centeredness not by throwing away his ego, but by incorporating it into a larger totality of life.
Nietzsche contended that culture always shaped an individual’s conscience in definitive ways. C.S. Lewis dissented, contending that the conscience informs humans of their sin. Both were right, but only in part. Humans are creatures of their environment, i.e., culture. Thus, culture shapes conscience and is one expression of human finitude. However, conscience, an awareness of right and wrong, also presumes self-awareness. On occasion, humans exercise their limited autonomy to function in a self-centered manner instead of engaging in reciprocal altruism. John Patrick Diggins in Why Niebuhr Now quoting Reinhold Niebuhr writes that a human is always “tempted to deny the limited character of his [sic] knowledge and the finiteness of his [sic] existence.”
Biblically, the dominant metaphors for sin depict sin as missing the mark, falling short, or doing the wrong thing. Theologically, sin designates a turning away from God. Set against the backdrop of this naturalistic understanding of sin, the biblical and theological concepts of sin are still relevant in the twenty-first century.