Metropolitan Hilarios also said Muslims and Orthodox worship the same god.
He is in good company. AFAIK at least St. John Damascene said that too.
Then you appear not to have read St John's "Heresy of the Ishmaelites"? It is true that he has some company among Orthodox heirarchs who should know better. The God that the Mohammedans worship is not the Triune God that the Christian Orthodox worship as a reading of the New Testament and the Quran quickly illustrate.
The similitude of Jesus before God is that of Adam: He created him from dust, then said to him: "Be", And he was. sura 3, 59
In the beginning was the Word, and the Word was God. The same was in the beginning with God. All things were by Him; and without Him was not anything made that was made...... And the Word became flesh, and dwelt among us, (and we beheld His glory, the glory as of the Only-begotten of the Father), full of grace and truth. John 1:1-3, 14
Jesus the son of Mary was (no more than) an apostle of God. ....Say, not 'Trinity': desist: for God is One God: Glory be to Him: (Far Exalted is He) above having a son. Sura 4: 173
Whosoever believeth that Jesus is the Christ is born of God: and everyone that Loveth Him that begat Loveth Him also that is begotten of Him..... For there are Three that bear witness in Heaven, the Father, the Word, and the Holy Spirit, and these Three are One. John 5: 1, 7
How then can anyone, clergy or lay, say that the God worshipped by the Mohammedans and the Christian Orthodox are one and the same?