WITHOUT God, there is no moral framework.
This seems to be Ravi Zacharias’s key point in his talk, Why I Am Not An Atheist. To illustrate this, he relates an incident from the early days in his career. He was giving a talk at the University of Nottingham when a student stood up and declared, “There cannot be a god because there’s too much evil in this world.”
So Ravi replies. “Wait a minute, when you say there's evil, aren't you assuming there's such a thing as good?”
The student says “Yes.”
Ravi then says, “When you say there's such a thing as good, there's such a thing as a moral law on the basis of which you can differentiate good and evil?”
The student hesitates at this, but is later forced to acquiesce and acknowledge a moral law.
Ravi then continues with, "But if you assume a moral law, you must posit a moral lawgiver, but that's whom you're trying to disprove and not prove. But if there's no moral lawgiver, there's no moral law. If there's no moral law, there's no good. If there's no good, there's no evil. What is your question?"
This shuts the student up and delights the audience to whom
Ravi is relating the story as they acknowledge his clever reply with cheers and applause.
This is what is called the Moral Argument (or at least one version of it) and it is often used by Christian apologists as some sort of trump card to point out that atheists/agnostics (who are mostly naturalists), have no business talking about morality, or good and evil -- because these are not supposed to exist for them, or do so only in a relative fashion.
Since there is no objective moral law giver, good and evil become merely opinions and one is just as good as the other. We are like animals, “following the dance of our DNA,” as they like to quote famous atheist and biologist, Richard Dawkins.
My main contention with this sort of argument is that while it is indeed possible to argue philosophically that there MUST be an objective moral law-giver, this law-giver has not seen fit to definitively reveal to humans what these objective laws are. We are still left to fend for ourselves and discover and argue about what these supposed objective laws are -- thus rendering them virtually relative.
Note that the moral argument is generic and may be used by almost any sort of theist as long he believes in a god that is basically good and just. So a Christian, Muslim, Jew, Hindu, and so on may use the same argument and still come out at odds with each other -- as is the case in reality.
My friend Gelo used an argument from a game of chess. Both theist and atheist sees a chessboard with the pieces intact. They have no idea what the rules are so they make it up along the way. The difference is that the theist believes that there is a definitive rule-book somewhere for playing the game while the atheist believes that they can just make things up as they go along. But my point is that that neither rule-book nor rule-maker can be found in a way that is objectively verifiable. And until we are able to do so, then we are then bound by the rules we make up by ourselves and neither of us know any better.
Still the theist may contend that there is nothing stopping the atheist from breaking or changing the rules because he doesn’t believe there are objective rules anyway. E.g. “I’m tired of moving the knight in an L-shape so I’ll make it move in an S-shape now.” Yet I would argue that the theist can do the same thing with this sort of reasoning, “After praying and fasting about it, I believe the Lord has revealed to me that knights should not move in an L-shape but in an S-shape. I obey God rather than men, so I’m moving my knight in an S-shape whether you agree or not.” And we’re left with the same sticky situation.
So while I may grant the theist a philosophical victory in this case, it is of no practical use in reality because morality is still VIRTUALLY relative. Just look at the different ways different nations handle issues like divorce, abortion, same-sex marriage, euthanasia, and so on. If there were an objective right or wrong to these issues we don’t know it, and we can’t test it nor verify it as objectively true (at least, not in the same way that we can verify that the acceleration due to gravity is approximately 9.8 meters per second squared).
Of course, Christians would contend that the Bible IS the objective rule-book I’m looking for, but the only people who would agree with that would probably be Christians, so that doesn’t sound very objective to me. I have issues with the Bible which I outlined in two past articles called Illusions of Biblical Inerrancy and A Second Look At Biblical Inerrancy so you can Google those if you’re interested. For now, let it suffice to say that I find it highly suspect that the supposed objective guide for morality would deem it fit to lay down rules against eating crabs and shrimp (Leviticus 11), yet say nothing in objection to human slavery.