“I am of opinion that the revelation of God can only be established by the wisdom of the doctrine, not by miracles, or in other words by ignorance.”

Source: On the Completion of the Bunker Hill Monument (1843), p. 102

1840s, Heroes and Hero-Worship (1840), The Hero as Prophet

Act 10, sc. 4
The Devil and the Good Lord (1951)

Meanwhile, it is idle to be impatient or to indulge in system-making.

Introductory
The Grammar of Science (1900)

Sermon Two

Source: Autobiography of a Yogi (1946), Ch. 34 : Materializing a Palace in the Himalayas

Answer to a survey written by the French mathematician Jaques Hadamard, from Hadamard's An Essay on the Psychology of Invention in the Mathematical Field (1945). Reprinted in Ideas and Opinions (1954). His full set of answers to the questions can be read on p. 3 here http://www.pitt.edu/~jdnorton/Goodies/Einstein_think/index.html.
1940s
Context: The words or the language, as they are written or spoken, do not seem to play any role in my mechanism of thought. The psychical entities which seem to serve as elements in thoughts are certain signs and more or less clear images which can be "voluntarily" reproduced and combined. There is, of course, a certain connection between those elements and relevant logical concepts. It is also clear that the desire to arrive finally at logically connected concepts is the emotional basis of this rather vague play with the above-mentioned elements.... The above-mentioned elements are, in my case, of visual and some muscular type. Conventional words or other signs have to be sought for laboriously only in a secondary stage, when the mentioned associative play is sufficiently established and can be reproduced at will.

Revelation, when applied to religion, means something communicated immediately from God to man.
No one will deny or dispute the power of the Almighty to make such a communication, if he pleases. But admitting, for the sake of a case, that something has been revealed to a certain person, and not revealed to any other person, it is revelation to that person only. When he tells it to a second person, a second to a third, a third to a fourth, and so on, it ceases to be a revelation to all those persons. It is revelation to the first person only, and hearsay to every other, and consequently they are not obliged to believe it.
When Moses told the children of Israel that he received the two tables of the commandments from the hands of God, they were not obliged to believe him, because they had no other authority for it than his telling them so; and I have no other authority for it than some historian telling me so. The commandments carry no internal evidence of divinity with them; they contain some good moral precepts, such as any man qualified to be a lawgiver, or a legislator, could produce himself, without having recourse to supernatural intervention.
When I am told that the Koran was written in Heaven, and brought to Mahomet by an angel, the account comes too near the same kind of hearsay evidence and second-hand authority as the former. I did not see the angel myself, and, therefore, I have a right not to believe it.
When also I am told that a woman called the Virgin Mary, said, or gave out, that she was with child without any cohabitation with a man, and that her betrothed husband, Joseph, said that an angel told him so, I have a right to believe them or not: such a circumstance required a much stronger evidence than their bare word for it; but we have not even this — for neither Joseph nor Mary wrote any such matter themselves; it is only reported by others that they said so — it is hearsay upon hearsay, and I do not choose to rest my belief upon such evidence.
1790s, The Age of Reason, Part I (1794)

Source: Reason: The Only Oracle Of Man (1784), Ch. VI Section III - Rare and Wonderful Phenomena no evidence of Miracles, nor are Diabolical Spirits able to effect them, or Superstitious Traditions to confirm them, nor can Ancient Miracles prove Recent Revelations