Recently I was asked how How do you say “The Gates of Hell shall not prevail” and “no weapon formed against me shall prosper” in Hebrew?, and I replied that the expression the Gates of Hell is inherently foreign to Hebrew, because it is absent in the Jewish tradition.
The expression God is the greatest is similarly alien to the Jewish tradition, for at least two reasons:
1) To say “God is the greatest” implies that He is one of a category of some sort (e.g., gods), in which He is the greatest. But in Judaism, God is not the greatest, but unique—the One and Only—as reflected in the mantra of every observant Jew:
שמע ישראל ה’ אלוהינו ה’ אחד
(“Hear, O Israel: the Lord is our God, the Lord is One.”)
Size comparisons are for pagans. It’s something that Jethro, who has a simple-minded, pagan religious outlook, says to Moses after learning of the miracle of the Exodus (Exodus 18:11):
עתה ידעתי, כי-גדול יהוה מכל-האלהים
(Now I know that the Lord is greater than all gods: for in the thing wherein they dealt proudly he was above them.)
2) Size does not figure even in the manifestations of the Divine. When the prophet Elijah was summoned to an audience with God on Mt. Horeb (I Kings 19), God’s messenger said to him:
Go forth, and stand upon the mount before the Lord, and, behold, the Lord passed by, and a great and strong wind rent the mountains, and brake in pieces the rocks before the Lord; but the Lord was not in the wind: and after the wind an earthquake; but the Lord was not in the earthquake: and after the earthquake a fire; but the Lord was not in the fire: and after the fire a still small voice.
If God is measured by anything, it’s by holiness. As Hannah, mother of the prophet Samuel says (I Sam. 2:2):
אין-קדוש כה׳, כי אין בלתך
(Ain kadosh kaAdonai, ki ain biltekha= “There is none holy as the Lord: for there is none beside thee”)
Thus, if you had to find an elegant, poetic way of saying God is greatest in Hebrew, it would be along similar lines:
אין גדול כה׳
(Ain gadol kaAdonai = “There is none as great as the Lord”)