Humans are born with a conscience. Whether the Bible exists or not does not affect our conscience.
I have lived among aboriginal people who never heard of the Bible and couldn't have read one anyway. These people were very sweet natured, kind, caring, loving, and considerate. Once I was sitting with the women, and one of the children took something out of my backpack, this tribe did not have technology, they had almost no individual possessions. One child was playing with the object she took out of my backpack and another child tried to take it away and the first child hit the second child with the object.
The second child started crying and the first child screamed and threw the object on the ground as if it had suddently come alive and spouted fangs. The entire tribe was traumatized and the elders came and did rituals for the rest of the day, there was obviously a lot of consternation, and the elders talked a lot about what to do about this horrific act.
I asked one of the elders why this was such a big deal and I didn't quite understand everything he said but he kept pointing to his head and making a sign for "hurt" and pointing to the children and mimicing the hitting. Like "the idea of a child hitting another child hurts my head". He was obviously talking about the conscience. The child who hurt the other child was deeply hurt all day and cried and cried. We finally had to take the object from my backpack away from the tribe and throw it away, to get rid of the "evil thing".
It was very obvious that those sweet people were born with the notion that physical violence was an extremely "bad" act, they obviously had a conscience.