The first Noachide law is the prohibition against idolatry. If we were to list the prohibition that is the most fundamental in the Torah it is the prohibition against idolatry. Just as God’s existence is an essential axiom of the Torah that He is one is just as essential. Although God’s existence is not really treated in the Torah (because it is assumed), that He is One is. His unity is treated in the Torah mainly because it is so often either misunderstood or perverted by human beings.¹

When we strive to understand something what is it that we are, essentially trying to understand? When we are reading a work what is it that the author wishes to communicate? The message of the Torah doesn’t seem that it could be any clearer. There is one God. According to the Rambam, Rabbi Moses Ben Maimon, “For it is the principal object of the Law and the axis round which it turns, to blot out these opinions from man‘s heart and make the existence of idolatry impossible.”²

This is not just a God of a particular people, Israel, but the God of all mankind. In fact the goal of all should be the destruction of idolatry. Thus the Rambam says, “the actual abolition of idolatry is expressed in the following passage: ’Ye shall destroy their altars, and burn their groves in fire’ (Deut. vii. 5), ’and ye shall destroy their name,’ etc. (xii. 3). These two things are frequently repeated; they form the principal and first object of the whole Law, as our Sages distinctly told us in their traditional explanation of the words ’all that God commanded you by the hand of Moses’ (Num. xv. 23); for they say, ’Hence we learn that those who follow idolatry deny as it were their adhesion [probably too fancy a word for the general reader] to the whole Law, and those who reject idolatry follow as it were the whole Law.’ (B.T. Kidd, 40a) Note it.”³ Essentially the Hebrew Scriptures teach us that God is one, and nothing else is to be worshiped, even as an intermediary between us and the One God.

God’s unity is understood in three parts. First God is alone. Second, God is non-corporeal (not physical). Finally, God has a unique identity. Each of these parts must be examined separately.

God is alone.
The Ramchal, Rabbi Moshe Chayim Luzzatto, explained in his “The Way of God” that “It is impossible that there exist more than one being whose existence is intrinsically imperative. Only one being can possibly exist with this necessarily perfect essence, and therefore the only reason all other things have the possibility of existence is that God wills them to exist. All other things therefore depend on Him and do not have intrinsic existence” (Ramchal, 35).⁴

In his work the Ramchal is summing up these important arguments to give us a manageable framework within which we can understand certain things about God. These things are imperative in a quest for truth—specifically in religion. The Ramchal has expressed very beautifully the core understanding of Judaism. God is uniquely One, His existence is necessary because without it nothing else could exist.⁵

Some, such as Hindus, assume an eternal and not-created World "birthed" by another; this is not illogical, but starts with entirely different assumptions that are problematic, since it appears "objectively" that the Universe is not eternal but has a start.

God is non-corporeal
In the history of monotheism, which began with Adam and continues to this day, the beginning of error often begins by attributing some type of physical existence to God. Such error is often the result of misunderstandings of passages in the Torah such as God sees or stands, or knows.

At times the teachers of Israel have had to correct these misunderstandings. The Rambam in “The Guide for the Perplexed” covers this issue in great detail. According to the Rambam, “We have stated, in one of the chapters of this treatise, that there is a great difference between bringing to view the existence of a thing and demonstrating its true essence.”⁶ The fact that God existed and his essence, what He is, are often confused with physical bodies since, “That God exists was therefore shown to ordinary men by means of similes taken from physical bodies; that He is living, by a simile taken from motion, because ordinary men consider only the body as fully, truly, and undoubtedly existing; that which is connected with a body but is itself not a body, although believed to exist, has a lower degree of existence on account of its dependence on the body for existence. That, however, which is neither itself a body, nor a force within a body, is not existent according to man’s first notions, and is above all excluded from the range of imaginations.” and he goes on to say, “…The perception by the senses, especially by hearing and seeing, is best known to us; we have no idea or notion of any other mode of communication between the soul of one person and that of another than by means of speaking, i.e., by the sound produced by lips, tongue, and the other organs of speech. When, therefore, we are to be informed that God has a knowledge of things, and that communication is made by Him to the Prophets who convey it to us, they represent Him to us as seeing and hearing, i.e., as perceiving and knowing those things which can be seen or heard. They represent Him to us as speaking, i.e., that communications from Him reach the Prophets; that is to be understood by the term “prophecy,” as will be fully explained.”⁷

The Rambam’s meaning is that since human beings are limited in their knowledge of existence because we only have and express knowledge through our senses. Human beings often misunderstand the figures of speech in the Tanach about God. Therefore, when we say that God spoke to a prophet it is often understood by most people that God spoke to that prophet through the same organs of communication that we use to communicate with other humans. This is one of the origins of idolatry—wrongly attributing human activities to God. That is why the term ‘prophecy’ will be explained, later in the Rambam's book “The Guide for the Perplexed, to make it clear what is meant by communication between God and a prophet.⁸

God has a unique identity.
No other religion can make the claims of uniqueness that the God of Israel can. This unique identity is absolutely necessary when knowing the true God. Although there are religions that have claimed to be, in some way, servants of the same God as the one professed by the Jewish people, they cannot escape that God has established for Himself a unique identity. This identity is intrinsically connected with the Exodus and Sinai experiences. Not only that, but God is the God of the children of Israel. Although He is the God of all humanity, God identifies Himself with Israel since it is to them that He gave His Torah.

It is through this Torah, as said above, that all nations gain blessing and knowledge of God. Anyone that claims that their god is the same as the God of the Sinai revelation but this god was not known to the Children of Israel at Sinai, or that this god has a different chosen people, or that there is nothing holy about the Torah or that the Torah today is not the same as the Torah of yesterday, or claims that it is not necessary to keep the Torah, this person does not serve the same God of the Jewish people, and has misunderstood something essential about God.⁹

Other “gods”
God addresses Himself to the people of Israel on the issue of the other gods, those that the nations have created for themselves. God makes it clear that His unity is absolute. None of the gods of the nations¹⁰ can make any claim that God can. Not only that, God makes a stronger claim, that the other "gods" are not real at all, but just images of people's invention.

The Universal God
It is a mistake to think that God is the God of only one particular people. That was the claim of the pagan societies. Every people and culture possessed their gods. The powers of these gods were seen to rise and fall with that of their people. Typically the failure of a god to protect its people from the ill fortunes of war led to the people abandoning their god and serving that of their conqueror. If there is one God only, then He must be the God of not just one people; but of all people. God constantly reminds us throughout Scripture that the nations have not been forgotten. They are as much a part of His plan as Israel. The Rabbis teach that the world was created for the Jews so that they could receive Torah, but the Jewish people were created so that they could take that Torah to the world.¹¹

1. Hilchot Avodah Zarah V’Hakot HaGoiim 1:1

2. Rambam, Moreh Nevuchim (“Guide for the Perplexed”). (Dover Publications, Inc. New York) 1956. All quotes from Moreh Nevuchim are taken from this edition unless specified otherwise.

3. Moreh Nevuchim. 320

4. Derech Hashem (“The Way of God”)

5. The following verses attest that God is alone. Deuteronomy 4:35, 39; 32:39; I Samuel 2:2; II Kings 19:19; Isaiah 43:10-11; 44:6-8; 44:24; 45:5-6; 45:21-22; 46:5; 46:9; 48:11; Malachi 2:10; and Nehemiah 9:6

6. Moreh Nevuchim. 59

7. Moreh Nevuchim. 60

8. The following verses attest that God is not a physical being. Numbers 23:19; Deuteronomy 4:11-12; 5:23 I Kings 8:27

9. Examine the following verses concerning the unique identity of God.

The God of the Exodus and Sinai: Exodus 20:2-3; I Kings 8:60; II Kings 19:19; Isaiah 40:18; Isaiah 44:6-8; 44:24; Hosea 13:4; Joel 2:27; Malachi 2:10; Nehemiah 9:6 The God of Avraham, Isaac, and Jacob: Gen. 17:9; 26:3, 24; 28:13; 32:9; Exodus 3:6; 15-16; 4:5; 33:1 Lev. 26:42; Num. 32:11; Deut. 1:8; 6:10; 9:5, 27; 29:13; 30:20; 34:4; I Kings 18:36; 2 Kings 13:23; I Chr. 1:28; 16:16; 29:18; 2 Chr. 20:7; 30:6; Ps. 47:9; 81:4; 105:6, 9, 42; Is. 29:22, 41:8, 51:2The God that gave the Torah: Deut. 4:5-8; 10:12-13; Ps. 81:4 The Holiness of the Torah: Psalm 19:8-9 (7-8); 119:44, 72, 97, 155, 163, 165 The eternality of the Torah: Deut. 29:28 (29); Psalm 111:7-8; Ezekiel 11:19-20

10. The following verses mark out the differences between God and the gods of the nations. Deuteronomy 6:14; I Samuel 2:2; Isaiah 40:18; 40:25; 40:25; 43:10-11; 44:6-8; 46:5; Malachi 2:10; Psalms 81:8-9; I Chronicles 17:20

11. Review the following verses. I Kings 8:50; II Kings 19:19; Isaiah 45:21-22; Malachi 2:10