“Certain it is that a conviction, akin to religious feeling, of the rationality or intelligibility of the world lies behind all scientific work of a higher order. … This firm belief, a belief bound up with deep feeling, in a superior mind that reveals itself in the world of experience, represents my conception of God.”

Source: The Subtle Art of Not Giving a F*ck (2016), Chapter 6, “You’re Wrong About Everything (But So Am I)” (p. 133)

General introduction
The Leader on the Couch, 2011

As quoted in The Private Albert Einstein (1992) by Peter A. Bucky and Allen G. Weakland, p. 86
Attributed in posthumous publications

Postscript
1900s, The Varieties of Religious Experience (1902)
Context: The ideal power with which we feel ourselves in connection, the 'God' of ordinary men, is, both by ordinary men and by philosophers, endowed with certain of those metaphysical attributes which in the lecture on philosophy I treated with such disrespect. He is assumed as a matter of course to be 'one and only,' and to be 'infinite'; and the notion of many finite gods is one which hardly any one thinks it worth while to consider, and still less to uphold. Nevertheless, in the interests of intellectual clearness, I feel bound to say that religious experience, as we have studied it, cannot be cited as unequivocally supporting the infinitist belief. The only thing that it unequivocally testifies to is that we can experience union with something larger than ourselves and in that union find our greatest peace. Philosophy, with its passion for unity, and mysticism with its monoideistic bent, both 'pass to the limit' and identify the something with a unique God who is the all-inclusive soul of the world. Popular opinion, respectful to their authority, follows the example which they set.

1950s, Atoms for Peace (1953)

http://scienceblogs.com/pharyngula/2008/04/the_man_with_two_duhs_in_his_n.php
The man with two 'duh's in his name
Pharyngula
2008-04-03

Wording in Ideas and Opinions: Common to all these types is the anthropomorphic character of their conception of God. In general, only individuals of exceptional endowments, and exceptionally high-minded communities, rise to any considerable extent above this level. But there is a third stage of religious experience which belongs to all of them, even though it is rarely found in a pure form: I shall call it cosmic religious feeling. It is very difficult to elucidate this feeling to anyone who is entirely without it, especially as there is no anthropomorphic conception of God corresponding to it. The individual feels the futility of human desires and aims and the sublimity and marvelous order which reveal themselves both in nature and in the world of thought. Individual existence impresses him as a sort of prison and he wants to experience the universe as a single significant whole. The beginnings of cosmic religious feeling already appear at an early stage of development, e.g., in many of the Psalms of David and in some of the Prophets. Buddhism, as we have learned especially from the wonderful writings of Schopenhauer, contains a much stronger element of this. The religious geniuses of all ages have been distinguished by this kind of religious feeling, which knows no dogma and no God conceived in man's image; so that there can be no church whose central teachings are based on it. Hence it is precisely among the heretics of every age that we find men who were filled with this highest kind of religious feeling and were in many cases regarded by their contemporaries as atheists, sometimes also as saints. Looked at in this light, men like Democritus, Francis of Assisi, and Spinoza are closely akin to one another.
1930s, Religion and Science (1930)
Context: Common to all these types is the anthropomorphic character of the idea of God. Only exceptionally gifted individuals or especially noble communities rise essentially above this level; in these there is found a third level of religious experience, even if it is seldom found in a pure form. I will call it the cosmic religious sense. This is hard to make clear to those who do not experience it, since it does not involve an anthropomorphic idea of God; the individual feels the vanity of human desires and aims, and the nobility and marvelous order which are revealed in nature and in the world of thought. He feels the individual destiny as an imprisonment and seeks to experience the totality of existence as a unity full of significance. Indications of this cosmic religious sense can be found even on earlier levels of development—for example, in the Psalms of David and in the Prophets. The cosmic element is much stronger in Buddhism, as, in particular, Schopenhauer's magnificent essays have shown us. The religious geniuses of all times have been distinguished by this cosmic religious sense, which recognizes neither dogmas nor God made in man's image. Consequently there cannot be a church whose chief doctrines are based on the cosmic religious experience. It comes about, therefore, that we find precisely among the heretics of all ages men who were inspired by this highest religious experience; often they appeared to their contemporaries as atheists, but sometimes also as saints. Viewed from this angle, men like Democritus, Francis of Assisi, and Spinoza are near to one another.

1940s, The World As I See It (1949)