The Transcendental Argument for God (TAG) is a philosophical argument, mainly developed by the late Gregory Bahnsen, and developed for the layperson in Dr. Jason Lisle's recent book The Ultimate Proof of Creation. Dr. Lisle promotes the argument as being philosophically impregnable--irrefutable. This argument is by no means successful in all situations. It will not work on opponents who are especially stubborn or ignorant. An opponent must be intelligent enough to understand that he has been defeated, and honest enough to admit that he has no refutation to the transcendental argument. That noted, against open-minded intellectuals, this argument is a devastating counter to any claim of morality, logic, or uniformity coming from a critic.
The Transcendental Argument merges somewhat with the Argument from morality, Contingency, and the Kalam cosmological argument. It is, however, distinct. All other philosophical arguments for God implicitly assume the TAG to be correct in order to be successful.
The basic claim is very simple: If the Biblical Worldview is not correct, then it is impossible to know anything. Of course, this may sound silly to some, but the basis for this claim is that God reveals in the Bible that, and sometimes why, everything that we take for granted is indeed correct. These are such things as uniformity in nature (not to be confused with uniformitarianism; uniformity simply states that under identical conditions, identical results can be expected), laws of logic, laws of mathematics, imminent morality, preconditions of intelligibility (to which the first three in the list belong), etc. Dr. Lisle maintains that if a person denies that the Bible is true (and therefore that God has not revealed Himself to mankind), then it is impossible to explain why these laws exist. Lisle emphasizes, moreover, that it is not simply enough for a deistic god to exist, because if this was the case, then it would be impossible to know that these things are true anyway--what is required is a personal, revealed God, such as the one who reveals Himself to mankind via the Holy Bible.
Lisle takes great pains to make it clear that it is not a profession of belief in the Biblical Worldview that is required, but merely that the Biblical Worldview (the belief that what the Bible says is completely true) is true. To accomplish this, he employs an analogy:
He asks the reader to imagine a critic of air. The critic denies that air exists, but it is immediately apparent to us that he is wrong: if air didn't exist, his voice wouldn't be able to travel through the air in the form of sound waves in order for us to understand him, not to mention that he would suffocate without air. In order for his argument to make any sense to his opponent at all, the critic of air would have to be wrong. Such is the case with the critic of the Biblical Worldview. In order for him to argue at all (by obeying the laws of logic), he would have to be wrong (because he cannot account for the laws of logic, but his opponent can).
The Ultimate Proof of Creation, video by Dr. Jason Lisle (part 1 of 6).