God Caused Justice
Morality involves the study of the universal recognition that "good" is better than "evil," which logically requires the existence of an ultimate Judge. That is, since all humanity accepts the knowledge that some events and standards are better than others—even though cultures may differ on what those events or standards may be—there must be an ultimate Source of such thinking, even if the absolute standard has become distorted over time.
C.S. Lewis, one of the most prolific writers and thinkers of our time, wrote of what he called "Moral Law," or the "Law of Human Nature" in his work Mere Christianity.
The Moral Law, or Law of Human Nature, is not simply a fact about human behavior in the same way as the Law of Gravitation is, or may be, simply a fact about how heavy objects behave. On the other hand, it is not a mere fancy, for we cannot get rid of the idea, and most of the things we say and think about men would be reduced to nonsense if we did. And it is not simple a statement about how we should like men to behave for our own convenience; for the behavior we call bad or unfair is not exactly the same as the behavior we find inconvenient, and may even be the opposite. Consequently, the rule of Right and Wrong, or Law of Human Nature, or whatever you call it, must somehow or other be a real thing—a thing that is really there, not made up by ourselves (Page 20).
We find then that we do not exist on our own, that we are under a law, and that Somebody or Something wants us to behave in a certain way.
Therefore, this Somebody or Something is directing the universe, and as a result we sense an internal law that urges us to do right and makes us feel responsibile and uncomfortable when we do wrong. We have to assume this entity is more like a mind than it is like anything else we know, because after all, the only other thing we know is matter and you can hardly imagine a bit of matter giving instructions.
Catholic apologist and philosophy professor Peter Kreeft also writes in his work The Argument from Conscience, "The only possible source of absolute authority is an absolute perfect will." The full text of Argument can be viewed here.