What exactly is sin?

I must say.. I'm getting rather tired of being called a sinner.  Just the other day a theist (Christian, of course) that I didn't know from a bar of soap stopped me on the sidewalk on my way to get lunch.  He intended to give me a small booklet containing a whole bunch of bible verses.  I've seen hundreds of them before in my life and I respectfully declined.  When he asked me why I declined the book, I told him in the friendliest and most respectful manner humanly possible that I didn't want the booklet, because I never bought into any religions - I'm an atheist.  This brought on a very disgusted expression on this chap's face, then he called me a sinner.  My first instinct was to give him a fat klap, but I resisted and carried on my way.

On my way back to work I started remembering other times religious people accused me of being a so-called sinner and this has happened MANY times before.  In forums, Facebook pages, bars and social gatherings, by just giving that one tiny piece of information (I'm an atheist), complete strangers have assumed and accused me of being a degenerate lowlife dishonest indecent trashy criminal who does not deserve to breathe.

This makes me wonder... I give to the homeless, I don't steal, I pay my taxes, I respect those who have shown they are worthy of respect, I have never cheated on any woman before and I don't intend on ever cheating on my wife, I take good care to help anyone who needs it and I try my best to not be a dick towards anyone.  I consider myself a good, kind-hearted person.  My understanding of sinning is doing bad things, but clearly according to christians I am a sinner and I'm not worth spit.

Christian News24 readers, please clear up my confusion.  Educate me.  What precisely is sin?  What makes people who do not believe in the deity of your particular choice such evil, evil people?
Wehr Wulf 2014/08/19 07:41:40 AM
I enjoy deliberately telling people I'm an atheist just so I can look at their facial expression and mostly it's reminiscent of the head cocked to the side my dog gives me when I talk to it.
Wehr Wulf 2014/08/19 07:45:23 AM
The very concept of sin comes from the bible. Christianity offers to solve a problem of its own making! Would you be thankful to a person who cut you with a knife in order to sell you a bandage? - Dan Barker
Thomas Freeman 2014/08/19 07:55:34 AM
Sin is what Jesus died to save your from. Seeing we don't know where he is and he has been absent for thousands of years sin must not be that important to him. So follow your conscience, you know what is right and you don't need some preacher man putting unnecessary guilt on your back, life is tough enough as it is without having to pay bribes to some preacherman to get you off the hook with a non existent God.
Morwen 2014/08/19 07:57:11 AM
I hope that you REALLY want an answer here. Have you ever told a lie, even a white one? Have you ever kept quiet when you should've spoken up? Ever had a speeding ticket? Spoken on your cellphone while driving? Gossiped, or done something you'd rather not brag about? Given a warm-klap to someone who offended you? etc... Because I have. I broke the law. Moral or otherwise, I have been guilty. I'm human, and its human to "err". Erring is not evil. Its embracing the dark side that is evil. Sin: transgression of a law. Evil: profound immorality, wickedness, and depravity, especially when regarded as a supernatural force.
Johann Johannes 2014/08/19 08:12:47 AM
hi Jimbo, "sin is the transgression of Gods law" 1John 3:4
Daisy Jones 2014/08/19 08:19:16 AM
He judged you therefore he sinned. It is not the place of a Christian to place judgement upon any other person. As Christians we are taught this by Jesus and our pastors should also teach this. Sadly though, you do get the fanatics who scream out ugly words and judge. I'm Christian and I've been called "sinner", "fake christian" and many other colourful names by fellow Christians.
Colleen 2014/08/19 08:25:55 AM
Sin is anything that a Christian doesn't like. Sin is something pleasurable that a Christian doesn't like other people to enjoy because their religion doesn't allow themselves to enjoy it. Or, sin is something a Christian likes very much but fearful of being found out by fellow Christians, they hide it behind false religious indignation. Sin is a word that was created by the christianity to control the adherents. Jimbo, being judged by a Christian [especially falsely!] is a SIN. :)
truthbetold221 2014/08/19 08:28:05 AM
Jimbo Slim, the reason anyone would tell that you're a sinner is because at that time you are the subject of the conversation, it's not that they are denying being sinners themselves. Any genuine Christian would never deny that and they would never look down on you because you're a sinner because they would know they are just like you. The only difference I have from you is that I have hope in what Jesus did; and that is he took the penalty of my sin. So you shouldn't be offended, I promise you we're all sinners. I realize that the question is "what is sin" ; sin is breaking of God's law/commands, which we all do.
Danie Theron 2014/08/19 08:36:43 AM
Jimbo maybe you should have taken the booklet and read it , I'm sure that would explain it but anyhow. Sin is transgression of Gods law. Jesus also showed people on sin in their lifes when He talked to them. Just think of the woman at the well....He showed her on her adultery...the rich young man....idolatry. The bible also says that the law of God is written in our hearts. Romans 2:15 "They show that the requirements of the law are written on their hearts, their consciences also bearing witness, and their thoughts sometimes accusing them and at other times even defending them." We are born into sin...we live in a fallen world. Romans 5:12 - Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned: Psalms 51:5 - Behold, I was shapen in iniquity; and in sin did my mother conceive me. Psalms 58:3 - The wicked are estranged from the womb: they go astray as soon as they be born, speaking lies. Romans 3:23 - For all have sinned, and come short of the glory of God;
Thanda 2014/08/19 08:44:35 AM
There are two ways in which sin can be defined. Broadly or narrowly: both are correct in their context. Suppose your son starts choking and you don't give the Heimlich Manoeuvre. Because you haven't done what you should have don't your son will likely die. Broadly speaking this is sin. If anyone does, thinks or says anything that is contrary to God's law, whether they know it or not and whether they believe are sinning. However suppose your friend is about to eat a drink from a carton of milk and you know it is spoilt. Suppose you don't tell him. Narrowly speaking this and only this is sin. When you act "against your better judgement" or when your act contrary to your OWN conscience (not someone else's, not even God's) then your are sinning. I hope this helped.