Argument from Conscience

[Redbeard The Pink]

One group says the bible, another only the new testament, a third the Quran…So, ultimately, the theist is left with subjective opinion…  An objective morality that is inaccessible is no better than no morality at all.  

What you are basically saying is that imperfect knowledge is no better than no knowledge at all. It would be like saying that because there are many different languages you cannot know anything about linguistics. Subjective moral reasoning, despite its flaws, has as its object some source of moral authority. Religious texts are an instrumental source of authority, tools religions use to gain knowledge of God, who is the ultimate and objective source of authority.

What you have in those texts is not an imperfect picture of an objective morality. It's still subjective morality because all these different scriptures exist, not to mention the fact that every sect (every person, in fact) interprets those texts differently. What we're saying is that, concerning objective morality, you do not have imperfect knowledge, nor does anyone; what you have is no knowledge because an objective source of moral truth cannot be shown to exist. There are objective facts from which we can try to derive morality (i.e. humans objectively exist, suffering objectively exists, empathy objectively exists, etc.), but the fact remains that an ultimate, universal, absolute source of moral guidance simply does not exist, or if it does we can't prove that it's ever spoken to us.