There are three fundamental laws of logic. Suppose P is any indicative sentence, say, “It is raining.” The law of identity: P is P.
The law of noncontradiction: P is not non-P.
The law of the excluded middle: Either P or non-P. The law of identity says that if a statement such as “It is raining” is true, then the statement is true. More generally, it says that the statement P is the same thing as itself and its different from everything else. Applied to all realty, the law of identity says that everything is itself and not something else. The law of non-contradiction says that a statement such as “It is raining” cannot be both true and false in the same sense. Of course it could be raining in Missouri and not raining in Arizona, but the principle says that it cannot be raining and not raining at the same time in the same place. The law of the excluded middle says that a statement such as “It is raining” is either true or false. There is no other alternative. The laws of logic are: Immaterial Transcendent Unchanging Universally applicable. To deny them is to use them therefore no person can rationally deny the existence of the laws of logic. The laws of logic flow from the biblical worldview. The very nature of God—unchanging, universal, and immaterial — is the source of the laws of logic. Being made in His image, we have the capacity to use these laws of logic to reason correctly and identify fallacious reasoning. On the other hand, naturalism does not provide any basis for the laws of logic, so the existence of these laws demolishes naturalism.