While discussing the moral argument a while back Violetwisp mentioned in the comments “I still don’t understand why you think the Christian belief system makes this any clearer.” The problem at hand is that we feel like there is some kind of standard of right and wrong that everyone should be held to but it is unclear exactly what the standard is or how we could discover it. As I’ve said before you can believe in objective morality without being theist, and you can certainly believe in it without being a Christian. So what do you do if you’ve followed the moral argument this far and accepted that there is such a thing as moral truth? What are your options?
Well the only real non-theistic option I’m aware of is that morality exists as a kind of Platonic Form. Though they aren’t very numerous at this period in time there are people who believe in Platonic Forms today. Some people even believe that mathmatics and numbers exist as something very like Platonic Forms. If you really want to understand what a Platonic Form is you’ll have to study some Plato, but my own butchered and ridiculously simplified version is that a Form is a non-material always-existing substance that embodies an ideal. Wow, that really was butchered. Let me try again: Forms theoretically exist outside of material reality but at the same time are connected to and reflect reality. Beauty, for example, is a traditional Platonic Form. Why do we find some things beautiful and some things ugly? Because the things we find beautiful have something in them that partially conforms to the Form of beauty. If something is ugly it deviates greatly from that Form. For Plato the Forms were arguably the only really real things in existence, and our world was a kind of shadow being cast by the forms themselves. One Platonic form is known as the Good. If an action resembles the Good then we recognize (in general) that it is good. If an action deviates from the Good then it is wrong, or evil. So it is possible that moral truth exists like this: that somewhere there is a concrete standard of good by which all actions can be judged.
Now what would happen if this absolute, immaterial standard of good was more than just a force of nature? What if Good was not a Form but a person? This leads to one of the other major options presented to us, and the option that the Christian traditionally takes. Christian theology teaches (again, I’m simplifying this a great deal) that goodness is that which aligns with the unchanging character of God. It’s important to note that the Christian believes that goodness is a property of God: just as wetness is a property of water. A human being can be good or bad, just as a dog can be wet or dry: but water by definition can’t be dry, and God by definition can’t be bad. To understand the Good is thus to understand a person: the greatest Personality of all, to be specific.
Now some Christians, and some other religions, have a different conception of how the Good might relate to God. Some would argue that good is whatever God commands: if God commands it then it becomes good. The problem with that theory is that it falls prey to what is known as the Euthyphro dilemma, which is named after one of Plato’s writings where Socrates debates morality with a man named Euthyphro. Socrates asks Euthyphro whether good is commanded by the gods because it is good, or whether it is good because the gods command it? If a god commands you to do something because it is good then that means that there is some greater standard of good that the god in question is abiding by. Thus the standard of Good must be something other than that god. However if something is considered good because that god commands it the morality is arbitrary. Perhaps the god in question will change his mind at some point: if so then suddenly what was once right is now wrong, and vice versa. If this is true then moral truth doesn’t really exist: we merely feel like it does because god told us to.
That’s why, if Christian theology has anything right at all, it must be right about Goodness being a property of God’s character if God is the source of moral truth. In this view God cannot do evil any more than water can stop being wet. He is the standard of Good itself.
So those are really the best two options that I’ve found for explaining the existence of moral truth. Either it is a Platonic Form or it is God himself. Now the Christians go one step further: they claim that Good loves humanity. The Good loves humanity so much that it became a human so that we could have a relationship with it. Christianity teaches that Goodness is not simply the standard by which actions are judged but is a living and active reality that wishes for us to become closer to it. Through such a relationship an individual flawed human can get closer to the Good and become like it.
So either Goodness is an illusion, an absolute, or a person.