"On what authority?" It is a very powerful question that cuts straight to the heart of most of the values issues relating to us today. If a person says that something is OK (or not OK), it is the simple question that cuts through everything else and gets straight to the heart of the matter. For me, on the issues the Bible addresses, the answer to the question is clear, "Because God says so in His written Word." But, for someone who rejects the Bible as God's written Word and as inerrant, we must simply ask them what makes the things right they say are right, or wrong that they say are wrong . . . "On what authority?"
When I was at West Point I was not a Christian, and I concentrated in philosophy. I remember thinking, for a season, that I was a moral relativist after hearing about that line of thought. I found myself saying, "Why not? What is right for some is right for them, and what is right for others is right for them." An officer there, who I many years later found to be a Christian, talked to me in private and told me that if he truly thought I was a moral relativist he'd do his best to have me removed from the academy. He said it was a very dangerous position to hold, especially for people who will be in positions of influence. I was stunned. I was rocked to my core. To me it was as simple issue of debating philosophy and playing with different belief systems, and he saw it as deeply serious.
Today, I couldn't agree with him more. Moral relativism—the idea that people come up with what is right for them and their culture—is incredibly dangerous and can lead to societies that euthanize the elderly, abort babies, selectively eliminate races, enslave certain classes, etc. And it comes from determining what is right for them. But, moral relativism is a philosophy predicated on error. It ignores that there is one God who is Lord of all, and who defines right and wrong. It ignores that there are absolute rights and wrongs. It ignores that we are accountable to our Creator, and that there is someone bigger than us. It ignores the fact that, in the end, it will not matter if we think something is right or wrong, but only what He thinks is right or wrong.
The quickest way that I know to cut to the chase and find out the core philosophy or foundation of someone and their arguments is to ask the most basic of questions . . . "On what authority do you base your opinion?"