Ancient Greek translates “sin” as to miss the mark. So to sin means to miss the mark or miss the point of human existence. It means to live unskillfully, blindly, and thus to suffer and cause suffering.
The ego wants more than it wants to have. Once it has, then it continues wanting more.
Original sin is that disconnectedness, that forgetfulness of our oneness with The Source.
-Eckhart Tolle