Hilchot Tefilla - Truth when talking about God

When R. Hanina and R. Jonathan were visiting certain towns in Judea, they came into a synagogue and observed that a reader was saying in his public prayer: "The God, great, mighty, and awful, glorious, powerful, and majestic." They silenced him, saying: Thou hast no right to add words to the form of the benedictions as fixed by the Sages. Whence do we know the proper form of the benedictions? From Moses, our master, who said: "The great God, the mighty, and the awful" (Deut. 10:17), to which the Sages added the form of the benediction used by our Father Abraham, "God Most High, Maker of heaven and earth" (Gen. 14:19).

Jeremiah, [in his order of prayer], said, "The great, the mighty God" (Jer. 32:18), but not "the awesome God." …because the Temple of which it is said "Awesome is God out of thy holy place" (Ps. 68:36) - was destroyed. Where, then, is the awe, if enemies came into His house and were not awed? Daniel, [in his order of prayer], said, "O Lord, the great and awesome God" (Dan. 9:4), but not "God the mighty." Why not? Because, as Daniel asked: When His children were put in chains, where was God's might? …However, when the men of the Great Assembly arose, they restored the manner of praising God's greatness to its ancient form, saying: "Now, therefore, our God, the great, the mighty, and the awesome God" (Neh. 9:32). Why? Because, as they explained, God remains above every praise by which men would exalt Him. R. Jacob ben R. Eleazar said: As for Jeremiah and Daniel, they knew of their God that He was truth-loving and did not attempt to flatter Him. However, the praise wherewith Moses our master praised Him is sufficient.