(In response to a couple of persons recently asking me to comment on my understanding of the Trinity, here is a fairly concise answer for those who already know that it is probably true, but are not intellectually confident as to how and why.)
As for the Trinity, I think your statement holds a clue to its truth: “Adonai can not be limited by the human limits of understanding.” Since the concept of God as a 3-in-1 is so outside of human understanding — and no normal person would think it up or expect others to go along with it — then it must be a revelation from the triune God, YHVH, Himself. By faith we understand God’s Word to be true and truth, and God gives many examples in the world to fathom the possibility of its being so. For instance, TIME is present, past, and future: 3 that is necessary for the 1 to be what TIME is. Human beings, created in the image of God, are 3 — body, soul, and spirit — that is 1 whole person. There are many such examples, which I am sure that you are also familiar with. God, of course, is still ‘other’, and He, as a great mystery, came in the flesh by the conception of the Holy Spirit in the person of Jesus Christ, who did not pray to Himself, but to His Father in Heaven. Therefore the need for a revelation of this holy and unique, one, true, living God which He has given to us that we might worship Him in spirit and truth.
When Abraham ate lunch with YHVH, he ate lunch with the Angel YHVH, who appeared in the likeness of human form, along with the other two angels. These pre-incarnate appearances of the Lord were all angelic, even though He looked like a Man often times. The conception and birth of the Lord through the virgin Mary is what gave Him the name Yeshua, which means that He is the Savior: He will save His people from their sins. For this He had to come as a flesh-and-blood human being, for angels, which are spirits, can not redeem humans. The name of Yeshua/Jesus applies to the Son of God being also the Son of Man in His humanity. Even He will receive a new name that we will know in the world to come.
The Hebrew word ‘echad‘ (אחד) does convey a plural unity. The number ‘1’ is made up of numerous ‘fractions’, such as 1/3, 2/3, 3/3 = 1. A cube is measured by its height, length, and width — and God being ‘equal’ in His unity and Deity, we can consider that 1 x 1 x 1 = 1. He is ONE, not three separate entities being added together to make 3. The Hebrew word to denote ‘one only’, or ‘unique’, is yachid (יחיד). This word is used to describe YHVH as the only true God; Isaac as Abraham’s ‘only’ son; Yeshua as God’s ‘only begotten Son’. Each of these is unique in their ‘one onliness’.
One more example which has helped me understand by faith the truth of God’s revelation — even though its full comprehension remains beyond human capability — is the first Hebrew word for ‘God’ used in the first sentence of the Bible — Elohim (אלהים). This word is plural, but the word for ‘created’ here in Genesis is singular, so already there is something unusual being expressed by the Holy Spirit’s inspiration. Linguistically, the specific form of plurality in this Hebrew word implies three or more; and we know that it is three in this case. YHVH God NEVER uses plurality in some Gentile way of speaking ‘royally’; and even if He does somewhere that I have missed, for Him it is also true! In most pagan religions, their gods are just that, plural in number — the gods. In Islam, their God is never expressed as a plurality; they have made him only a singular, like the Hebrew words also used for God, such as El and Eloha (אל; אלוה). That religion denies and rejects the love of the truth of the one, living, God; and, sadly, Rabbinic Judaism has done the same.The Creator of the Universe and the Redeemer has given a revelation of monotheism that is not defined simply as the belief in one God: the true one YHVH God — “Hear, O Israel, YHVH our God(s), YHVH is one.” The true ‘one God’ is truly unique. He is the God which both the Old and the New Testaments bear witness to. It is the Spirit of YHVH that has inspired all the writers of the Holy Scriptures. Yeshua/Jesus is YHVH/LORD, the Son of the Living God. He and the Father are one in essence, and it is this unity of the Godhead that Yeshua prayed will be in those who are the Body of Messiah/Christ. Amen, Amen. Truly, there is none like Him!