By Metropolitan Hierotheos of Nafpaktos
In Islamic teaching there is talk of one God, who has no son. It emphasizes, therefore, the uniqueness and inaccessibility of God. God cannot have a son or a daughter. On the Mosque of Omar in Jerusalem is written the commandment: "Praise be Allah who has not taken unto himself a son." In the Koran it is repeatedly said: "Your God is One God; there is no god but He, the All-merciful, the All-compassionate." The teaching of the Koran on this subject is summarized as follows, "He, Allah, is One. Allah, on whom all depend. He has not begotten, nor was He begotten. And none is comparable to Him.”
In Orthodox teaching we speak of the trinity of God, of the three persons of the Holy Trinity, who constitute distinct hypostasises. Hypostasis is essence with the characteristic unique feature. All three persons of the Holy Trinity are Divine. Monotheism is not abolished, precisely because the persons of the Holy Trinity have the same uncreated essence and because the Son was born from the Father before the ages, and the Holy Spirit proceeds from the Father and is sent through the Son. The persons do not abolish the one and only essence, and the essence is not disintegrated by the existence of persons. Also in Orthodoxy we talk about the essence and the uncreated energies, with which God comes into contact and communion with creation. Through the uncreated deifying energy of God, man can achieve deification, the real relationship with God.
Source: From the book Γέννημα και θρέμμα Ρωμηοί (Born and Bred Romans). Translation by John Sanidopoulos.