“The perversity of the universe tends towards a maximum. The universe is hostile.”

Book 4; Universal Love III
Mozi
Context: Now, as to universal love and mutual aid, they are beneficial and easy beyond a doubt. It seems to me that the only trouble is that there is no superior who encourages it. If there is a superior who encourages it, promoting it with rewards and commendations, threatening its reverse with punishments, I feel people will tend toward universal love and mutual aid like fire tending upward and water downwards — it will be unpreventable in the world.

Ninth Memoir. On Several Convenient Forms of the Fundamental Equations of the Mechanical Theory of Heat.
The Mechanical Theory of Heat (1867)

introduction to De Curvis Elasticis, Additamentum I to his Methodus Inveniendi Lineas Curvas Maximi Minimive Proprietate Gaudentes 1744; translated on pg10-11, "Leonhard Euler's Elastic Curves" https://www.dropbox.com/s/o09w82abgtftpfr/1933-oldfather.pdf, Oldfather et al 1933
Context: All the greatest mathematicians have long since recognized that the method presented in this book is not only extremely useful in analysis, but that it also contributes greatly to the solution of physical problems. For since the fabric of the universe is most perfect, and is the work of a most wise Creator, nothing whatsoever takes place in the universe in which some relation of maximum and minimum does not appear. Wherefore there is absolutely no doubt that every effect in the universe can be explained as satisfactorily from final causes, by the aid of the method of maxima and minima, as it can from the effective causes themselves. Now there exist on every hand such notable instances of this fact, that, in order to prove its truth, we have no need at all of a number of examples; nay rather one's task should be this, namely, in any field of Natural Science whatsoever to study that quantity which takes on a maximum or a minimum value, an occupation that seems to belong to philosophy rather than to mathematics. Since, therefore, two methods of studying effects in Nature lie open to us, one by means of effective causes, which is commonly called the direct method, the other by means of final causes, the mathematician uses each with equal success. Of course, when the effective causes are too obscure, but the final causes are more readily ascertained, the problem is commonly solved by the indirect method; on the contrary, however, the direct method is employed whenever it is possible to determine the effect from the effective causes. But one ought to make a special effort to see that both ways of approach to the solution of the problem be laid open; for thus not only is one solution greatly strengthened by the other, but, more than that, from the agreement between the two solutions we secure the very highest satisfaction.

"Grizzly Man" (2006)

Source: Cosmos (1980), p. 250

The Hour of Decision (1933)

Hazel's Dad, p. 213-214
The Fault in Our Stars (2012)

Multiple variations of this quote can be found, but the earliest one on Google Books which uses the phrase "friendly or hostile" and attributes it to Einstein is The Complete Idiot's Guide to Spiritual Healing by Susan Gregg (2000), p. 5 http://books.google.com/books?id=XLQ8X67PozAC&lpg=PP1&pg=PA5#v=onepage&q&f=false, and this book gives no source for the quote.
A variant is found in Irving Oyle's The New American Medicine Show (1979) on p. 163, where Oyle writes: 'There is a story about Albert Einstein's view of human existence. Asked to pose the most vital question facing humanity, he replied, "Is the universe friendly?"' This variant is repeated in a number of books from the 1980s and 90s, so it probably pre-dates the "friendly or hostile" version. And the idea that the most important question we can ask is "Is the universe friendly?" dates back much earlier than the attribution to Einstein, for example in Emil Carl Wilm's 1912 book The Problem of Religion he includes the following footnote on p. 114 http://books.google.com/books?id=nWYiAAAAYAAJ&pg=PA114#v=onepage&q&f=false: 'A friend proposed to the late F. W. H. Myers the following question: "What is the thing which above all others you would like to know? If you could ask the Sphinx one question, and only one, what would the question be?" After a moment's silence Myers replied: "I think it would be this: Is the universe friendly?"'
Misattributed

Source: A Confederacy of Dunces