I would have to disagree with a chronological definition of this. I agree with you,in that it is up to God. He alone is the Judge of our innocence. Again I look at "He that knoweth to do right and doeth it not, to him it is sin." Without the knowledge, there is no sin, only innocence. I hope I was correct in my quotes, because they were from memory.
I dont know what you mean by disagreeing with the chronological definition...
But I believe that just because you are ignorant of the law and sin, doesnt mean you are not going to be held accountable for it.. its like getting pulled over in your truck and being cited for something you didnt know was a law.. does that make you exempt from the law... no... but it is cool when you receive grace and are let go for it.. I believe God does the same thing in certain instances... do I know which ones they are,.. no...
When you say sin is sin to one person and maybe not the other... as in drinking... I disagree... sin is sin. Its all sin and its all equal in Gods eyes.. we dont determine what is and what is not sin.