Think about your conscience. Before you do something that is either right or wrong, your conscience tells you which one it is. You then choose to do it or not, whether or not it is right or wrong.
My wife grew up in a household where table manners were well enforced. When we go to a restaurant, she sometimes makes comments about egregious violations of proper etiquete. Her comments mainly consist of admonitions of that person's parents for not "teaching their child proper conduct". (hmmm....sins of the fathers?...but I digress)
Your statement about conscience appears to assume that we are somehow born with a sense of what is right and what is wrong. However, protomenace is saying that your environment is the very thing that develops your understanding of right and wrong (conscience). I think that most research supports protomenace's position.
With this developed (vice inborn) sense of right and wrong, are we completely responsible for our violations of particular rules in the Bible when we were not brought up to believe that those particular rules were valid?
Related to this is the idea of belief itself. If we were brought up to require evidence before accepting statements as true, are we completely responsible for our disbelief of something that has scant or no evidence to support it?
In other words: God knows us and what our limitations are, yet He does not provide enough evidence of His existance to overcome those limitations for people who require more than unsupported assertions. Because our limitations do not allow us to "simply believe", God will punish us for all eternity (AOG POV). Is this version of God cruel or loving?