The God of Abraham was always a singular being, always ECHAD (one). Abraham knew him as El Shaddai, God almighty. The Israelites knew him by name, the yad hey and vav hey (too sacred to even type out). "Elohim" is like the word deer: one deer many deer. You know which it is via context and grammar.
For most Jewish people, the "Shema" is the foundational verse for the concept of a monotheistic God. It is the very heart of Judaism, and serves to confirm, in the Jewish mind, that there cannot be anything other than one God. The Shema verse is found in Deuteronomy 6:4, and says:
"Hear, O Israel: The Lord our God is one Lord."
In Hebrew it reads, "Shema Yisrael Adonai Elohenu Adonai Echad." The word Shema is the first Hebrew word in the passage and means "hear." At first glance this seems to support the Jewish concept of a monotheistic God. However, a careful examination of Deuteronomy 6:4 actually establishes, rather than refutes, the plurality of God. In fact, the Shema verse actually presents one of the strongest arguments for the tri-unity of God in the entire Bible. Here's why.
The last word of the Shema verse is echad, which is translated into English as the word "one." This is what is known as a compound-unity noun - that is to say, a noun which demonstrates oneness or unity, but at the same time can contain two or more entities. A number of scriptural examples will help make the point.
Genesis 2:24, speaking of the union of Adam and Eve, reads: "For this reason a man will leave his father and mother and be united to his wife, and the two will become ONE flesh." Here, the Hebrew word that is used for "one" (one flesh) is the same word for "one" that is found in the Shema verse - echad.
It clearly speaks of the unity of more than one person into a united, or singular, entity.
In Genesis 1:5, Moses used this same word when he described the first day of creation: "And God called the light day, and the darkness He called night. And the evening and the morning were the first day." This "one" day, or "first" day is the Hebrew word echad. The one day referred to was comprised of both light and darkness - evening and morning.
And still another example is found in Jeremiah 32, verses 38-39 which reads, "And they shall be my people, and I will be their God;
And I will give THEM ONE HEART." Here, the many people are given "one" (echad) heart. A unity of two or more individuals into oneness.
Interestingly, however, there is another Hebrew word which signifies an absolute oneness, or singleness. That word is yachid. It is found in such scriptures as Genesis 22:2 (only son - one son), in Proverbs 4:3, in Judges 11:34, in Jeremiah 6:26, Amos 8:10, and in Zechariah 12:10 - "....and they shall mourn for him, as one mourns for an only son." So considering that the Old Testament is the inspired word of God, Jehovah had a choice of using a word that implies singularity (yachid), or plurality in oneness (echad). He chose echad to make his point, so that it might be understood there is a plurality in union.
"Deuteronomy 6:4 does not deny the Trinity but rather establishes one of the planks of the Trinity: there is one God.
God bless!
