Cognitivism and non-cognitivism are discussions about the nature of language and whether our claims about the world are truth-apt (can be either true or false).
The problem of religious language considers whether it is possible to talk about God meaningfully, especially if the traditional conceptions of God as being incorporeal, infinite and timeless are accepted.
The attitude that God is ineffable has inspired many theologians to adopt the via negativa (also known as apophatic theology), which involves only employing negation/denial when talking about God.
Ayer's theory of meaning is predicated on the Verification Principle, which states that a sentence is meaningful if and only if it is an analytic truth or it is verifiable through sense experience.
Under the strong verification principle, statements like "All bachelors are unmarried", "There are mountains on the other side of the moon", "All men are mortal", and "Electrons carry negative charge" are meaningful.
The Verification Principle, as stated by Ayer, states that a sentence is meaningful if and only if it is an analytic truth or can be verified through sense experience.
John Hick offers an analogy in response to Ayer’s verificationism, stating that two men are traveling along a road, one believes it leads to the Celestial City, the other believes it leads nowhere.
Ayer contends that "God-talk is nonsense", arguing that if God is something that cannot be meaningfully described, then even if a Mystic experiences God, they still won't be able to give a meaningful description of their experience.
According to Ayer, nothing can be done to test the truth or falsehood of the Mystic's visions or encounters with God, they must be considered meaningless.
If we weaken the falsification principle as being "evidence that merely counts against the truth of a claim", then we are simply talking about the verification principle again, as verification is about finding evidence that reduces as well as supports the possibility of the claim.
A statement is meaningful if the probable truth of statements can be established through observation or we know in principle what observation is required to ascertain its truth, even if we cannot currently do so.
A statement is directly verifiable if it is an observation statement itself or it, along with some other observation statements, entails an observation statement that cannot be entailed by those others alone.
Ayer claims that the verification principle is a criterion of meaning, a claim about the nature of statements, and its truth may be determined through the arguments of its implications.