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 to influence, the phenomenal world. Man sought to alter the disposition of these gods in his own favor by means of magic and prayer. The idea of God in the religions taught at present is a sublimation of that old concept 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. Nobody, certainly, will deny that the idea of the existence of an omnipotent, just, and omnibeneficent personal God is able to accord man solace, help, and guidance; also, by virtue of its simplicity it is accessible to the most undeveloped mind. But, on the other hand, there are decisive weaknesses attached to this idea in itself, which have been painfully felt since the beginning of history. That is, if this being is omnipotent, then every occurrence, including every human action, every human thought, and every human feeling and aspiration is also His work; how is it possible to think of holding men responsible for their deeds and thoughts before such an almighty Being? In giving out punishment and rewards He would to a certain extent be passing judgment on Himself. How can this be combined with the goodness and righteousness ascribed to Him?(Albert Einstein, Science, Philosophy, and Religion, A 1934 Symposium published by the Conference on Science, Philosophy and Religion in Their Relation to the Democratic Way of Life, Inc., New York, 1941; from Einstein's Out of My Later Years, Westport, Connecticut: Greenwood Press, 1970, pp. 26-27.)
As for the negation of the Christian Trinity in the Quran - and this negation is extrinsic and conditional - we must take account of certain shades of meaning. The Trinity can be envisaged according to a "vertical" perspective or according to either of two "horizontal" perspectives, one of them being supreme and the other not. The vertical perspective- Beyond-Being, Being and Existence - envisages the hypostases as "descending" from Unity or from the Absolute - or from the Essence it could be said - which means that it envisages the degrees of Reality. The supreme horizontal perspective corresponds to the Vedantic triad Sat (supraontological Reality), Chit (Absolute Consciousness) and Ananda (Infinite Beatitude), which means that it envisages the Trinity inasmuch as It is hidden in Unity(1). The non-supreme horizontal perspective on the contrary situates Unity as an essence hidden within the Trinity, which is then ontological and represents the three fundamental aspects or modes of Pure Being, whence the triad : Being, Wisdom, Will (Father, Son, Spirit).Now the concept of a Trinity seen as a deployment (tajalli) of Unity or of the Absolute is in no way opposed to the unitary doctrine of Islam ; what is opposed to it is solely the attribution of absoluteness to the Trinity alone, or even to the ontological Trinity alone, as it is envisaged exoterically. This last point of view does not, strictly speaking, attain to the Absolute and this is as much as to say that it attributes an absolute character to what is relative and is ignorant of Maya and the degrees of reality or of illusion ; it does not conceive of the metaphysical - but not pantheistic - identity between manifestation and the Principle; still less, therefore, does it conceive of the consequence this identity implies from the point of view of the intellect and the knowledge which delivers.(1) The Absolute is not the Absolute inasmuch as it contains aspects, but inasmuch as It transcends them; inasmuch as It is Trinity It is therefore not Absolute.