sin is a religious concept, handed down by some divine force to tell us what is or is not right or wrong. Eating meat(pork) to a Christian could seem fine but to a Jew it is wrong, or Hindu(I think its Hindu) eating Beef is wrong. If one is not religious that in itself is a sin, the question posses to much on the metaphysical, psychological and philosophical. What is it mean to sin, what is it mean to be moral etc etc
when you mean sin, what sin against god? or God? or perhaps even gods, sin against man, sin against nature. Question is to vague.