I understand that G-d has many names and you can call Him by any one of them. Why do you say He has only one name?
We say He has one Name because He tells us so. Psalm 83:18, “That men may know that thou, whose name alone is Yahweh, art the most high over all the earth.” Later in the Psalms we find, “Let them praise the name of Yahweh: for his name alone is excellent; his glory is above the earth and heaven,” Psalm 148:13.
The notion that he has many names really has polytheistic overtones. Heathen religions are noted for their many deities, all with names customized to suit each flavor of religion. Paul said there are “gods many and lords many,” Contrarily, Israel knew Him as the one, true Mighty One, and they called on Him by His one true Name. Isaiah 42:8 says, “I am Yahweh: that is my name: and my glory will I not give to another, neither my praise to graven images.” His true Name is the defining factor for True Worship. If we can’t even get His Name right, how can we get His worship right? How can we say we even worship Him if we don’t call on His real Name?
He tells us that “Yahweh” is His Name forever and His memorial unto all generations, Exodus 3:15. A memorial is how we remember or think about someone. Every Scriptural title attributed to Yahweh is connected to His true Name: Yahweh Elyon, Yahweh Nissi, Yahweh Yireh, etc. By believing that He has many names we believe that any name is acceptable to him, including generic titles like “God,” which is not a Hebrew term but a Germanic title. It is absent in the older Biblical manuscripts. That He has many names equal to His Name is simply untrue and unscriptural.
Knowing and calling on His Name means that we become His people, and that means forming a personal bond with Him. That bond is expressed by His own mouth, “My people shall know My Name,” Isaiah 52:6. “Therefore they shall know in that day that I am he that does speak: behold, it is I.” Beyond that, Yahweh said that His people will be called by His Name, Daniel 9:19.
When you understand that His relationship with His people is considered a marriage covenant, then it makes perfect sense that His spiritual bride would take on his name just as a bride does her husband’s.
Ezekiel 39:7 reads, “So will I make my holy name known in the midst of my people Israel; and I will not let them pollute my holy name any more: and the heathen shall know that I am Yahweh the Holy One in Israel.”