The truth that God is One is the cornerstone of the First Commandment: thus far we have come in our search for God’s revelation of Himself in His law. Remembering this principle, we are also able to understand that idolatry in any form is an act of gross rebellion against God. Never does the idolatrous practice of the heathen reflect a search for God as the One, True God; rather, as Paul tells us in Romans 1, it is always a refusal to worship God as He reveals Himself in His creation. By this refusal the truth concerning the Only God is changed into a deliberate and malicious lie. 

This principle that God is One has several different aspects. It means, first of all, that God is indeed the Only God and the True God. He is not one God among many, but He alone is God and there is no other god beside Him. It is this teaching that has made the Christian faith so offensive among men. The religions of this world may claim priority for their gods, but at the very least they are always willing to recognize the existence of the gods of others. Our own Constitution takes somewhat this same neutral position when it guarantees freedom of religion, thus implicitly recognizing the “equality” of all religions. Over against this, Christianity has insisted that the gods of the heathen without exception are idols and that there is no God but Jehovah, and that therefore the Christian religion is the only true religion and the only way of salvation. This has been, then, one of the reasons why Christianity has been universally despised and persecuted.

Also implied in this truth are the simplicity and sovereignty of God. God’s simplicity (cf. the Belgic Confession, Art. I) means that all of God’s attributes and works are in perfect harmony with one another and with the perfection of His own being. There is no contradiction or division in Him. His justice and His mercy, for example are never at odds with one another in His work of salvation. He is One in Himself. His sovereignty is the crown of both these other truths. Because He is the Only God, He is also the “blessed and only Potentate,” the only sovereign King and Lord. And because He is perfect and complete in Himself, so that all His attributes, works, and will are in perfect unity and harmony, He is perfect also in dominion and power. This is implied in Deuteronomy 6:4, where God not only teaches His people that He is One, but that He is One Lord.

These other aspects of God’s Oneness, however, do not stand on the foreground in the First Commandment. They are the principles that lie behind other of the Commandments, notably the Fifth and the Tenth. Here, in the First Commandment, the important truth is that He is the Only, True God. 

The connection between the First Commandment and this truth that God is One is made in Deuteronomy 6:4-15. The positive principle of the First Commandment is verse 4: “Hear, O Israel: the Lord, our God is one Lord.” From this principle flows forth both the positive and negative requirements of the First Commandment. The positive command comes first: “And thou shalt love the Lord thy God with all thine ,heart, and with all thy soul, and with all thy might . . . . Thou shalt fear the Lord thy God, and shalt serve Him, and shalt swear by His name” (verses 5 and 13). That which is forbidden follows: “Ye shall not go after other gods, of the gods of the people which are round about you” (verse 14). 

God taught this truth, that He is the only God, to Israel in many different ways. He taught them not only through His Word as we read it in such passages as Deuteronomy 6, but He gave them one place and one manner of worship all through the Old Testament, that Israel might never forget that her God was the One God. Even today He reveals that to us when He teaches us that there is but one Name given under heaven by which we may be saved and but one way to come to the Father. He is One God. 

We ought also to take special note of the positive instruction in Deuteronomy 6. Here we see very clearly that although the First Commandment itself is negative, nevertheless obedience is also positive. It is simply not enough to refrain from idolatry and to have no other gods, but we must have Him as our God with all our heart and soul and strength. We must have Him as our God by loving, fearing, and serving Him. 

That this positive requirement is first and foremost, is also clear from Deuteronomy 6. The First Commandment is expressed negatively, not because the negative is more important, but because the law’s first purpose is to teach us our sin and misery. 

In one word, the positive requirement of the First Commandment is “worship.” In using that word, however, we immediately face the danger of thinking of worship as something tucked away into some small corner of our life and reserved for Sabbath observance, or for a few hours of private meditations during each day. Deuteronomy 6 makes it clear that this “worshipping” of the One True God is something for all of our life. He requires that we love, fear, and serve Him not only with our heart and soul, but with all our might—in other words, with the strength of our physical life as we exert ourselves in all the duties and responsibilities that God has given. We must worship Him when we sit in our houses, when we walk by the way, when we lie down, and when we arise. This Commandment concerning God’s worship is to be bound to our hands while we work and is to rule all the use of our eyes as “frontlets.” It is to be the first thing we remember when we return to our homes and the last thing of which we are reminded as we leave, just as though it is written in large letters on the door and on the gate. 

There is a whole commentary on the First Commandment to be found in chapters 43 through 45 of the prophecy of Isaiah. The principle of the First Commandment, that God is the Only, true God is repeated no fewer than eight times in chapter 43 and the first eight verses of chapter 44 (Isaiah 43:3, 10, 11, 12, 13, 15Isaiah 44:6, 8). In verses 9-20 of chapter 44 this fundamental truth is contrasted with the foolishness of idolatry, all summed up in verse 20: “He feedeth on ashes: a deceived heart hath turned him aside, that he cannot deliver his soul, nor say, Is there not a lie in my right hand?” Then in the last verses of chapter 44 and in chapter 45 this great principle is repeated another seven times to drive it home to the hearts of God’s people for their eternal comfort and salvation (Isaiah 44:24Isaiah 45:5, 6, 14, 18, 21, 22). 

This all-important truth about God becomes, then, the basis for all the instructions, admonitions, and warnings that are found in these chapters. Because He alone is the Lord, Israel’s God (Isaiah 43:3), Israel is commanded not to be afraid (Isaiah 43:1, 5), but to glorify God (verse 7), to know Him and believe Him (verse lo), to witness concerning Him (verse 12), to praise Him (verse 21), to call upon Him and honor Him (verses 22, 23), and to remember Him (verse 26). Again in chapter 44 Jacob and Israel are commanded to remember and return to the Lord Who formed them (verses 21, 22). In chapter 45 God instructs them concerning the necessity of knowing Him (verse 6), of looking to Him, bowing before Him, and swearing only by His Name (verses 22, 23). They must confess that they have all things from Him (verse 24), and glory in Him forever (verse 25). All of these things come down to the one great requirement of the First Commandment, that we have Jehovah to be our God and that we worship and serve Him alone in every walk and way of life. 

To fail in any of these things is as much idolatry as any of the grosser forms of sin against this First Commandment, such as the worship of heathen gods, sorcery, fortune-telling, superstition, prayers to saints or angels. As much as superstition denies that God is the One Lord Who controls all the circumstances of our life, by so much does our failure to seek and expect all good from Him alone do the same. Just as much as sorcery and fortune-telling deny Him by seeking the help of other powers beside Him, by so much does our failure to trust in Him alone and to submit to Him with humility and patience do exactly the same. To forget Him at any time, to fall short of His glory and honor in any activity, to forget to praise Him and know Him, to seek or trust in anything else besides Him, though ever so little, is an much idolatry as the worst of the practices of the heathen. 

This Commandment, then, serves the purpose for which it was given. By revealing God in all His glory as the only God and Savior, it uncovers the depth of our depravity and shows that our whole life is full of idolatry. We are no different from Israel who worshipped on every high hill and under every green tree in the promised land. In seeking and loving the things of this world we sacrifice even our children to these idols, as Israel did to Moloch. Possessions, children, families, work and wealth, power and honour, all can and do become our idols whenever we love them, trust in them, or seek them next to or beside the One, True God. This Commandment uncovers our sin in all its filthiness, We are shown to be those who have turned aside to our own ways and gone astray from God, saying in our hearts, as the fool, though we may not dare to say it openly, that there is no God. In all our own works our idolatrous practices reveal our idolatrous hearts and both heart and works are laid bare by this Word of God.

Nevertheless, in teaching God’s people their sin—and indeed, they are the only ones who can and will understand what this Commandment teaches—the First Commandment is their schoolmaster to bring them to Christ. It does this first of all by teaching them that, as the worst of idolaters, they have no hope apart from God’s great grace. Then too the law shows them what Christ has done in bringing that grace. He has born all the wrath of God against those who worship aught but Him, and in so doing has nailed our idolatrous nature to His cross and crucified through His suffering and death its continual enmity against God. Above and beyond that, He has rendered to God on their behalf a new and perfect obedience to the First Commandment. He did that when only 12 years old by putting His Father’s business before all other things in His life. When He faced Satan in the wilderness He refused to receive the Kingdoms of the world with all their glory in any way which conflicted with the truth that God alone must be worshipped and served. In His agony in Gethsemane, when the bloody sweat was pressed out of His body, He loved, feared, worshipped and glorified God, when He said, “Thy will be done.” And finally when He laid down His life and when the weight of God’s wrath pressed upon Him all the torments of Hell, He made it all an act of perfect worship and adoration, for even then it was, “My God, My God . . . . ” 

He had no other God but Jehovah that we might have no other. He reveals in all His work the One, True God beside Whom there is no God or Savior, and through Him our obedience to the First Commandment becomes a daily confession that Jehovah alone is God. It cannot be otherwise, for He has revealed Himself in Christ as the One God, our Savior. In thankfulness we confess that there is none like Him by renouncing and forsaking our idols and by serving and worshipping Him with all our heart and soul and mind and strength. The thankful confession of our moth and of our life is that, “Asshur shall not save us; we will not ride upon horses, neither will we say any more to the work of our hands, Ye are our gods: for in Thee Alone the fatherless findeth mercy” (Hos. 14:3). Hear, O Israel, the Lord our God is One Lord.