A band of people who called themselves the logical positivists came up with a principle and with it attempted to totally disprove the whole of religion. Their claim was that religious language is totally devoid of meaning.
The principle they came out with, they called the verification principle. What it said was, a statement has meaning if, and only if, it can be proved or disproved sensually. This was their main argument against religious language. Indeed, this was the one argument against religious language, that it cannot be proved or disproved, therefore it is devoid of meaning. Anthony Flew argued from this angle.
In John Wisdom’s Parable of the Garden, in an essay he titled ‘Gods’, written in 1944, there are two men- a man who believes a gardener visits the garden unseen and unheard, giving order and life to the garden, and a sceptic, who doesn’t believe in the gardener he, or any other person, has never seen. Flew uses the sceptic in this parable to illustrate his point. How, exactly, does an invisible, intangible gardener differ from no gardener at all?
His other argument against religious language was religious believers will let nothing count against their beliefs then they cannot be proved because they cannot be falsified.

Basil Mitchell’s response to this was him trying to prove that religious believers do actually see things that count against their beliefs. Only they don’t believe these things ultimately count against their beliefs.
R. M. Hare coined the term ‘blik’ to describe a state of lunacy where you will not allow anything to count against your beliefs. This was what Mitchell argued- that religious believers do not have bliks.
He gives the parable of the resistance movement and the stranger. A member of the resistance movement of an occupied country meets a stranger who claims to be the resistance leader. The stranger seems truthful and trustworthy enough to the member of the resistance movement, and he places his trust in him wholly. The stranger’s behaviour is highly ambiguous, and at times his trust is tried, at other times his trust in the stranger is strengthened. This is how Mitchell’s parable differs fro Hare’s. In his own words, ‘the partisan admits that many things may and do count against his belief: whereas the lunatic who has a blik about dons doesn’t admit that anything counts against his blik. Nothing can count against bliks.’
His argument is straightforward- religious beliefs are a matter of fact which can be proved or disproved. The stranger knows whose side he is on. After the war the ambiguity of the stranger’s behaviour will be resolved. In the same way, the existence or non-existence of God, or his love or apathy for us, or his benevolence or malevolence will be proved one day—only after death, and not before. In this way Mitchell proved how religious language is totally meaningful. All that remains is to prove its truthhood or falsity.