I think everyone has come back with good points and added important things to the sin list.....
Heres my contribtion:
In response to what the Vatican/pope has announced...
I believe there are no 'new' sins...
If you read the Bible, its all in there.
Only Jesus himself, being of God could clarify everything that is under the canopy of sin..but God in the Old Testament, and Jesus all through the New Test, summed up in nutshells for us what sin is...everything that seperates us from God, for God is pure.
Jesus said (to a crowd that was going to stone a woman for committing adultery), "you who have not sinned, cast the first stone...". If we recognise our own sin and want to repent of it, thats the important part. Even if we recognise our sin, it still doesnt give us the right to judge others. Teaching is what people need, not condemation.
Anything that KEEPS us from being pure in mind is sin.
Witchcraft, worship of anything, not being able to forgive is one...this could be used in all situations, as can judging others.
Loving ones neighbour for example, means to treat them in ALL ways that we ourselves want to be treated like....that includes, well everything...no idol chat, gossiping, judging, lying, hate....all these come under the title of sin..
God hates ALL types and severity of sin..not just the big stuff like murder, hate, rape etc...but of course they are all sin too.
Its 'original sin' which we are born with (a naturally sinful nature) that was in the beginning which is what we need to re nounce..then accept that we are still in the flesh, and are responsible for own own actions...but ask for Gods help to learn how to be more like Jesus every day....we cant do it without help, because our nature is 'fallen'..and only by Gods grace, He makes us more like Himself.
God looks at the heart, and like it or not we all have a conscience...and therefore we are going to be answerable to whatever we do, unless we repent. God is a God of mercy, yes of judgement too, but He wants to forgive and forget, so we are able to have a relationship with Him.
If we are trying our best to stay on the straight and narrow..He knows.
You could make a list as long as your arm listing all that is considered sin....but if its not from the Bible...people will interprete and justify what they think is sin..this wont work, because of our corrupt nature...we can only go by Jesus' guidelines.
We are only responsible for ouselves. in our hearts we should know whats right or not.