It is the work of the Holy Spirit to bring back into the conscious mind the things that are stored in the subconscious. In studying the Bible, never think that because you do not understand it, therefore it is of no use. A truth may be of no use to you just now, but when the circumstances arise in which that truth is needed, the Holy Spirit will bring it back to your remembrance.
The preacher should not enter his pulpit claiming to have received a revelation; his claim should be that he is a man who reads the Word and prays and believes that the Holy Spirit illumines and enlightens his understanding, with the result that he has a message for the people.