APOLOGIST: "Objective moral values must exist, because if they don't, then that means we have no basis on which to assert the morality or immorality of something."
ME: "I have my own opinion and moral codes. I find some things to be moral, and others to be immoral."
APOLOGIST: "But that's not objective! That's your opinion. I could just say my opinion is the opposite of yours, now we're even. Why should I care what your opinion is?"
ME: "Why should I care what YOUR opinion is? If I think killing is right (based on my opinion), and you think it's wrong (based on your opinion), then I could disagree with you and my opinion would be that your opinion is wrong."
APOLOGIST: "Yeah, exactly! It's all just word salad. It means nothing because it's subjective. But my opinion is based on an objective moral authority, my god, and so it has more weight."
ME: "What if I say that my opinion is based on an objective moral authority, bestowed upon me by my god, and so IT has more weight? We're back to square one. How do you decide who is telling the truth?"
APOLOGIST: "The Christian god is the only god that is just, because Christian morality is based on the grace of God and Jesus Christ, not based on actions."
ME: "Okay, so what if I say that my opinion ALSO comes from the Christian god? How do we tell which of us is correct?"
APOLOGIST: "We just look in the Bible and see what it says. Like for example, it says, 'thou shalt not kill,' so we know that killing people is objectively wrong."
ME: "But the Bible requires a lot of context and history to understand. I could easily just say that you misinterpreted what the Bible says --- the original Hebrew word used in that commandment, for example, more closely translates to 'murder', not 'kill,' and murder is defined as a wrongful killing; "wrongful killing is wrong" is just a tautology, so how do we decide what is wrongful and what is justified?"
APOLOGIST: "You just have to look elsewhere in the Bible. All the answers are in the Bible, you just have to read it with an open and unskeptical mind."
ME: "Alright, let's just skip ahead and take for granted that everything you say is true, that the Bible is flawless and that there is 'objective morality' and killing is wrong, and the Bible tells us how and when and why. My question to you, then, is: Why should I care?"
APOLOGIST: "Because it's wrong, by definition!"
ME: "So? What does that mean? How is that any different from saying that someone THINKS it's wrong by definition?"
APOLOGIST: "Because it's OBJECTIVE!"
APOLOGIST: "So you're saying you don't care what's right or wrong?"
ME: "I'm saying your definition of 'objectively moral' is meaningless. Speaking objectively, it has no more weight in reality than anyone's opinion. It's just as easily discarded, and it reflects nothing physical that can be confirmed scientifically. It has no criteria or results that can be assessed in context with one another, and so its value cannot be objectively determined. It's utterly meaningless, unless you choose to accept it of your own accord --- just like my opinion."
APOLOGIST: "Yeah, but there are consequences for not doing what is moral according to the Bible. You'll go to hell."
ME: "I could threaten you with a gun if you don't accept my opinion, so now there are consequences for not doing what is moral according to me."
APOLOGIST: "But your consequences are temporary. God's consequences are eternal; hell never goes away. You can only die once."
ME: "So it's a matter of power? God's decree is moral because he has more power to use for punishment than anyone else?"
APOLOGIST: "No, it's moral because it's god's law!"
APOLOGIST: "This conversation is stupid."
ME: "Yes. Yes it is. I'm glad we've reached that understanding."
CONCLUSION: Here's the thing....in this world, the Appeal to Morality DOESN'T work as a binding principle. If you tie me up and tell me you're going to kill me, and I say, "Please don't, that would be immoral, because god says it's immoral," and you kill me anyway, what has changed? How is that situation any different from the same situation, but in a world where objective values don't exist, other than consequence? If consequence is the only reason you think something is immoral, you're reducing morality to "might versus right," which is not an issue of morality at all but rather of who has the most power to assert his or her own (subjective) opinion.