In the “prophetic” religions (Judaism, Christianity, Islam, and Zoroastrianism), revelation is conceived as a message communicated by God to an accredited spokesman, who is charged to herald the content of that message to an entire people.
The media by which revelation occurs are variously conceived. Most religions refer to signs, such as: auditory phenomena, subjective visions, dreams, and ecstasies.
In the prophetic religions, revelation is primarily understood as the “Word of God,” enabling the prophet to speak with certainty about God’s actions and intentions.
Argument from Revelation
God communicated messages to certain individuals.
Those messages were written down, forming revelatory texts.
Thus the latter hypothesis is more likely, putting the burden of proof on proponents of the supernatural explanation of the text. That means proving that the text is so extraordinary that it could not have been produced by human beings alone.
If a text were the word of God, everything it says would be true. Any doubtful passage casts doubt on its divine origin. Worse, passages contradicting each other prove the text can’t be the word of God. Consider the argument, derived from Bart Ehrman’s Misquoting Jesus, page 10:
If the New Testament is the word of God, everything it says is true.
If every statement in the New Testament is true, then:
Jesus died the day after the Passover meal, per Mark 14:12,15:25.
Jesus died the day before the Passover meal, per John 19:14.
Jesus could not have died both the day before and the day after the Passover meal.
Therefore, the New Testament is not the word of God.
Appeal to Faith
That the religious texts are the word of God must be accepted on faith.
For Aquinas and Calvin faith is accepting theological propositions as divinely revealed. Aquinas and Calvin both understand faith as (or as essentially involving) the grasping of propositionally expressible truths as divinely revealed through willingly receiving God’s gracious gift of that very revelation.
“FAITH is the assent to any proposition, not thus made out by the deductions of reason, but upon the credit of the proposer, as coming from God, in some extraordinary way of communication. This way of discovering truths to men, we call REVELATION.” (Enquiry Chapter XVII of Book IV)
“Now faith is the substance of things hoped for, the evidence of things not seen.”