U are right.
I've arrived rather late to the conclusion that 'sin' is a man made concept.
There is no such thing. Only karma and the law of cause and effect.
As one guru recently said "If one is willing to accept the consequences of one's actions, then... do whatever."
An animal or fish eats another - where is the sin?
Life feeds on life - in this world of duality, Yin and Yang are always in play.
dc