Einstein did once comment that "God does not play dice [with the universe]." This quotation is commonly mentioned to show that Einstein believed in the Christian God. Used this way, it is out of context; it refers to Einstein's refusal to accept the uncertainties indicated by quantum theory. Furthermore, Einstein's religious background was Jewish rather than Christian.

A better quotation showing what Einstein thought is the following: "I believe in Spinoza's God who reveals himself in the orderly harmony of what exists, not in a God who concerns himself with fates and actions of human beings."

Einstein was unable to accept Quantum Theory because of his belief in an objective, orderly reality: a reality which would not be subject to random events and which would not be dependent upon the observer. He believed that Quantum Mechanics was incomplete, and that a better theory would have no need for statistical interpretations. So far no better theory has been found and evidence suggests that it never will be.

A longer quote from Einstein appears in Science, Philosophy, and Religion, A Symposium, published by the Conference on Science, Philosophy, and Religion in Their Relation to the Democratic Way of Life, Inc., New York, 1941. In it he says:

The more a man is imbued with the ordered regularity of all events the firmer becomes his conviction that there is no room left by the side of this ordered regularity for causes of a different nature. For him neither the rule of human nor the rule of divine will exists as an independent cause of natural events. To be sure, the doctrine of a personal God interfering with natural events could never be refuted, in the real sense, by science, for this doctrine can always take refuge in those domains in which scientific knowledge has not yet been able to set foot.

But I am convinced that such behavior on the part of representatives of religion would not only be unworthy but also fatal. For a doctrine which is to maintain itself not in clear light but only in the dark, will of necessity lose its effect on mankind, with incalculable harm to human progress. In their struggle for the ethical good, teachers of religion must have the stature to give up the doctrine of a personal God, that is, give up that source of fear and hope which in the past placed such vast power in the hands of priests. In their labors they will have to avail themselves of those forces which are capable of cultivating the Good, the True, and the Beautiful in humanity itself. This is, to be sure, a more difficult but an incomparably more worthy task ...

Einstein has also said:

It was, of course, a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.

The latter quote is from Albert Einstein: The Human Side, edited by Helen Dukas and Banesh Hoffman, and published by Princeton University Press. Also from the same book:

I do not believe in immortality of the individual, and I consider ethics to be an exclusively human concern with no superhuman authority behind it.

Of course, the fact that Einstein chose not to believe in Christianity does not in itself imply that Christianity is false.