In the field of cosmic revelations the causes for mistake are many and the possibility of error is great. The occurrence of these revelations is as good as their non-occurrence.
You may ask how it is that sometimes error creeps into the revelations of the saints, and something different actually happens. A saint informs, for instance, that so and so will die after a month or return home from his journey. But when the month is over neither happens.
The answer is that the revelation may depend for its occurrence upon certain conditions whose details the recipient of the revelation could not discover, yet he told about it in categorical terms.
There may be another possibility: The Gnostic may come to know from the preserved tablet about a particular event, but that event might change, as it belongs to the category of conditional decrees of whose nature and liability to change he is unaware. In such a case, therefore, if he tells what he knows that might not happen.
Know that the decrees of God are two kinds: alterable and non-alterable. The former is subject to change and alteration, the latter is not. God says: ‘My decrees do not change.’[50:29] This refers to the non-alterable decrees. About the alterable He says: ‘He effaces what He will and confirms (what He will), and with Him is the Mother-Book.’ [13:39]