Yet to deliver the message of God is not merely to read what prophets and apostles penned and to repeat it by rote. The man who is to be God's messenger must himself draw near to God and abide in His secret, as they did. The word must detach itself from the book and become a living element of experience before it can profit even the reader himself; and much more is this the case, of course, before it can profit others.[28] It is the truth which has become a personal conviction, and is burning in a man's heart so that he cannot be silent, which is his message. The number of such truths which a man has appropriated from the Bible and verified in his own experience is the measure of his power.[29] There is all the difference in the world between the man who thus speaks what he knows from an inner impulse and the man whose sermon is simply a literary exercise on a Scripture theme, and who speaks only because Sunday has come round and the bell rung and he must do his duty. The selection of the theme for preaching is to be determined chiefly by the power of the Word to lay hold of the conviction of the preacher. Or, if the subject is prescribed, as when one is lecturing through a book of the Bible, the points to be treated are to be determined in this way. Sometimes, as a preacher reads the Word, a text will leap from the page, so to speak, and, fastening on the mind, insist on being preached upon. A sermon on such a text is nearly always successful; and a wise man will, therefore, take care to garner such texts when they occur to him. He will underline them in his Bible, or, better still, enter them in a note-book kept for the purpose, adding a few words perhaps to indicate the first lines of thought which have occurred to him. These notes may be multiplied from time to time; and, when the minister turns to a page which has been thus filled, he will often find his sermon nearly made to his hand.[30] Dr. Wendell Holmes tells of Emerson that he kept such a note-book for subjects on which he might lecture, and for suggestions of lines of thought which he might follow out. He called it his Savings Bank, because, though the payments into it were minute, they gradually swelled to riches; and passages which his hearers and readers supposed to be outbursts of sudden literary creation were really the results of slow accumulation. If this was necessary for even a genius like Emerson it will be far more necessary for the ordinary man. The gold of thought has generally to be collected as gold dust.