Authenticity of divine revelation

Theorem: It is utterly impossible to validate the authenticity of any divine revelation.

Note that this theorem does not deal with whether divine revelation exists. It only establishes that nobody can claim to have a genuine divine revelation and be certain that the revelation actually is genuine.

Lemma 1
Without checking the content of the message, it is impossible to distinguish between messages sent by an arbitrary Cartesian daemon and a message sent by a god.

Proof
We define a Cartesian daemon to be an (arbitrary) entity who is able to manipulate all of one's senses, dreams, and perceptions, essentially shaping the reality one perceives; or being an conscious intermediary between a person and the reality that person perceives.

Note that we only require the possibility that more than one such entity exists to complete the proof of this lemma.

There are several arguments for the possibility of existence of more than one or more of such entities given the existence of a god.


 * 1) Note that one can classify any omnipotent god being capable (the god may or may not actually do it, but such a god has such capabilities) of being a Cartesian daemon (therefore, at least one Cartesian daemon exists, given the existence of a god).
 * 2) The theodicy issue, or, the problem of evil. If any omnipotent god already rid the world of evil (Assumption: misrepresenting God is an evil act), then one can assert that such a being cannot exist because God removed its existence already.
 * 3) The habit of people accusing some arbitrary evil entity of obscuring religious figures for the purpose of trickery/faith testing.
 * 4) *Example: In Christianity, Justin Martyr asserted the claim that mythological figures that share similar features with Jesus are planted by the Devil to test people's faith/trick people into false faiths. (Never mind that this argument can be logically reversed into placing Christianity into the "false religion" section and the devil (Lucifer or Satan) being just as validly replaced by a malevolent- or trickster-entity from another mythology/religion (including one that has yet to gain fame or renown); see Number 4 for a summary of the fallacy used.)
 * 5) Asserting that God is the only omnipotent being involves the fallacy of special pleading.

It follows that
 * The method/channels a god chooses to send a message to someone can be used by any other Cartesian daemon(s).
 * No foolproof authentication method can be established since the authentication key has to be sent through one of those methods/channels without the possibility of some other Cartesian daemon imitating it.
 * The deity sending corrective messages in the event of impersonation won't help the problem; even if one message is followed by another message claiming that the first message was a fake and correcting the misinformation, it is still impossible to determine which of the messages, if any, is genuine.

Proof of the theorem
(This is for the monotheistic God. Proof for the case of other gods is similar.)

Suppose God is trying to send a message. How would the recipient determine the message is from God? Let's suppose the message is sent by X, so the task is to determine whether X is God.
 * Lemma 1 dictates that the only method to validate the message's authenticity is by checking the message's content. In this case, it is sufficient to attribute the message to God regardless the true identity of the sender.
 * Suppose the content of the message is checked. How would one determine whether it is from God?
 * If it lies in the realm of "God would/wouldn't say such a thing", it is compared to a separate list. In this case, since there is already a list on the receiver's end, the revelation is no longer "divine" (since someone else would have revealed it to the receiver already).

Corollaries

 * If morality is from a single supernatural source (God in this case), there is no way such a being can authentically communicate such a standard to anyone.
 * Proof: To attribute any particular moral value to come from God involves checking the moral value against some predetermined list. Since such a list already exists, it cannot possibly be revealed from God. The argument that the list originates from God suffers from the same problem of authenticity, so the chain of regress does not terminate with God.