I don't believe in sin. I don't believe I'm born with sin.
But I do have some kind of sense of right and wrong.
Most if not all of my sense of right and wrong is covered by law, e.g. I believe that driving a car after drinking 10 pints is wrong - and it happens that this is illegal, too.
I agree with LoveUniHateExams. Sin is an invention to keep people in line. Think about it, if you wanted to sell medicine to someone who wasnt even sick you'd need to convince them that they were sick and that you have the remedy. This is what religion does. In most religions they invented this idea of hell or eternal cutting off from God. The only way to not go there is do as i say. Keep them thinking that they're not worthy, that they're "dust", that they need God in their lives.
There are things i consider immoral and abhorrent that are legal. And there are illegal things that i have no problem with. I use my own morality, common sense and empathy to guide me.
I am my own God.