If Albert Einstein believed in anything he would call a "god," it wasn't the sort of god which religious theists today typically believe in. Einstein explicitly rejected the possible existence of any sort of "personal god" which could care about human existence, would interact with us, or would answer prayers. In fact, Einstein went so far as to argue that belief in such a god was a legacy of humanity's primitive existence when we created such supernatural beings to explain events around us.
In Science, Philosophy and Religion: A Symposium, Albert Einstein discusses the primitive origins of belief in personal gods:
During the youthful period of mankind's spiritual evolution, human fantasy created gods in man's own image who, by the operations of their will were supposed to determine, or at any rate influence, the phenomenal world...
The idea of God in the religions taught at present is a sublimation of that old conception of the gods. Its anthropomorphic character is shown, for instance, by the fact that men appeal to the Divine Being in prayers and plead for the fulfillment of their wishes...
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.
quoted in: 2000 Years of Disbelief, by James Haught
Unfortunately, as Albert Einstein notes, the continued presence of such beliefs today can cause harm. Impersonal gods with no interest in us and no effect on events around us would almost certainly not inspire the creation of grand religions around them. They would not lead to the development of powerful priesthoods with unaccountable clergy, to religious wars and crusades, to persecution, or any of the other many problems which religions cause today.
Unfortunately, the people in charge of transmitting and promoting religion are precisely those who personally benefit from religion remaining the way it is. Einstein asked that "teachers of religion" give up the doctrine of a personal God which has invested such "vast power" in the hands of teachers of religion. How many people would enter the priesthood in order to end the power of the priesthood rather than benefit from it? Albert Einstein's call is hopeful, but also unlikely to become reality.