In his analysis of the relationships between science and religion, Einstein identified three different concepts of God that correspond approximately to three different stages of the evolution of religious thought. The first concept of God was developed before human beings were conscious of the laws regulating the causal connections between natural phenomena. Therefore they invented anthropomorphic supernatural beings who controlled the course of events and were responsible for natural phenomena. The main motive for this conception of God was fear: the “fear of hunger, wild beast, sickness, death” (Ideas and Opinions, 39). Thus Einstein spoke of a “religion of fear” (40), in which people followed traditional rituals in the hope of gaining the benevolence of God.
Einstein called the second concept of God “the social or moral conception of God” (Ideas and Opinions, 40) because social and moral concerns are the main source of religious practice. God is the father who protects, rewards, comforts, and punishes his children and guarantees the immortality of the human soul. An important task of this kind of religion, which is typical in modern times, is to justify the adoption of specific views of morality and to provide the context for advocating social justice.
Both the religion of fear and the moral and social conception of God are ingredients, in varying degrees, in all historical religions. Primitive religions are mostly, but not exclusively, based on fear, and contemporary religions are primarily based on moral and social concerns, though fear is also a motive force. In these contexts, a special caste—the priests—occupies the important position mediating between God and the people. The priests, who are instrumental in stabilizing the ritual of religion, are usually linked with political rulers and privileged classes, are in control of education, and guide people in their social behavior, crystallizing the division of society into classes.
In these two types of religious thought God is conceived of as an anthropomorphic being. Einstein identified this concept of a personal God as the main source of conflict between science and religion, because this concept of God conflicts with the main aim of science, that is, to establish unrestricted laws, which do not admit exceptions, governing the reciprocal connections of objects. These laws, which Einstein identified with causal laws, exclude the possibility of supernatural intervention: God cannot interfere with natural events. It is true, said Einstein, that science cannot definitely refute the conception of a personal God, because domains exist in which science has not been able to determine general laws. However, if religion restricts itself to these domains to protect itself from science, it will lose its influence on human society. Thus “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” (Ideas and Opinions, 52). Only thus it is possible to prevent a conflict between science and religion. A religious man is a man who has liberated himself from “selfish desires” (48) and is preoccupied with “superpersonal value” (ibid., 48), independent of any conception of a divine being.
Einstein called the third stage of religious thought the “cosmic religious feeling” (Ideas and Opinions, 41). God is not conceived of as an anthropomorphic being; in a sense, the only function of God is to guarantee the regularity of the universe. Among the forerunners of the cosmic conception of God, Einstein cited some books of the Bible (the Psalms of David, Prophets), Buddha, Democritus, Spinoza, and St. Francis of Assisi. No religious practice corresponds to this conception of God because it is futile to try to secure God’s benevolence. God does not interfere with natural laws, does not make miracles, does not reward human beings, does not punish them. This mature conception of God has its main source in the scientific contemplation of nature, which discloses the exact regularity of the causal laws of nature and thus renders inconceivable the conception of a God interfering with nature in order to reward and punish his creatures.
As concluded by Murzi, Einstein is not an atheist nor he is agnostic. I am sure that he is atheistic towards a personal god, but he obviously subscribed to the third type of cosmic god. For those Christians reading this, Einstein is atheist towards your god.
Einstein is my hero - I called myself Albert after him when I have the chance to name myself. However, I disagree with him on this issue. I think he is wrong. The concept of a cosmic god who has the intelligence to set the right parameters for this Universe to exist demands an explanation of the source of that intelligence. A being with a greater intelligence is needed to create the intelligent god and so on.
A possible theory of the existence of this Universe and the current human intelligence is evolution - small, gradual accumulation of changes through zillions of try and error. A localised imbalance of energy - in our case, solar energy reaching the planet Earth - prompt a chain of energy transfers in order to reach an equilibrium. Initially, we have the formation of simple molecules which, through chance, combined to form more complex molecules, which again by chance, evolved into simple biological cells and so on. There is no magic. We are just on the lucky branch of the evolution tree.
To throw you more food for thought, watch this from TED: