Where did you find that idea? And does it line up with what the Bible tells us? The interpretation that God will punish us in the afterlife isn't erroneous, because it's precisely what he said he would do if we refused to repent. Not sinning shouldn't be misconstrued as not knowing a religious way, and every person is naturally born religious/spiritual, but some of us have that part quelled by our environments or the people we're around at such a young age that they later come to believe they've always been non-religious or non-spiritual.