1. The ten precepts of the decalogue are conveniently distributed into those of the first and those of the second table. To the first table are attributed those precepts which immediately prescribe our duty towards God himself; of this kind, there are four. The second table claims those precepts which contain the duties of men towards their fellow-men; and to it are attributed the last six.
2. This is the relation which subsists between the commands of each table — that, from love to God and in reference to him, we manifest love, and the offices of love towards our neighbor; and if it should happen that we must of necessity relinquish either our duty to God or our neighbor, God should be preferred to our neighbor. Let this relation, however, be understood as concerning those precepts only which are not of the ceremonial worship; otherwise, [respecting ceremonies] this declaration holds good: "I will have mercy, and not sacrifice."
3. The first commandment is, "Thou shalt have no other god before my face," or "against my face."
4. It is very certain that, in this negative precept, the subjoined affirmative one is included or presupposed as something preceding and prerequisite: "Thou shalt have me, who am Jehovah, for thy God." This is likewise immediately consequent upon the preface, "I am the Lord thy God;" therefore, "Let me be the Lord thy God;" or, which is the same, "Therefore, have thou me, the Lord, for thy God."
5. But "to have the Lord for our God, is the part both of the understanding and of the inclination or the will; and, lastly, of an effect proceeding from both or from each of them.
6. "Another god" is whatever the human mind invents, to which it attributes the divinity that is suitable and appropriate to the true God alone — whether such divinity be essence and life, or properties, works, or glory.
7. Or whether the thing to which man attributes divinity be something existing or created, or whether it be something non-existent and merely imaginary and a figment of the brain, it is equally "another god" for the entire divinity of that other god lies radically, essentially and virtually in human ascription, and by no means in that to which such divinity is ascribed. Hence is the origin of this phrase, in Scripture, "To go a whoring after their own heart."
8. But this "other God" may be conceived under a three-fold difference, according to the Scriptures. For those who have him, have
(1.) either themselves been the first inventors of him,
(2.) have received him from their parents, or
(3.) from other nations, when neither they nor their fathers knew him; and this last is done either by force, by persuasion, or by the free and spontaneous choice of the will.
9. For this reason, that "other god" is truly called "an idol;" and the act by which he is accounted another god, is idolatry; whether this be committed in the mind, by estimation, acknowledgment, and belief, or by the affections, love, fear, trust and hope, or by some external effect of honor, worship, adoration and invocation.
10. The enormity of this sin is apparent from the fact of its being called "a defection from God," "a forsaking of the living fountain," and "a digging of broken cisterns that hold no water," "a perfidious desertion of holy matrimony," and "a violation of the connubial compact." Nay, the gentiles are said to sacrifice to devils whatsoever they suppose that they offer to God, in this ignorance of God and alienation from the life of God.
11. The cause why men are said to do service unto devils, although they have themselves other thoughts, is this: because Satan is the fountain head, and origin of all idolatry; and is the author, persuader, impeller, approver and defender of all the worship which is expended on another god. Hence, likewise, it is the highest degree of idolatry when any one accounts divine or ascribes divinity to Satan as Satan, displaying himself as Satan and vaunting himself for God.
12. But though the gentiles worshipped angels or devils, not as the supreme God, but as minor deities and his ministers, by whose intervention they might have communication with the supreme God; yet the worship which they paid to them was idolatry, because this worship was due to no one except to the true God. But it does not belong to the definition of idolatry, that any one should pay to another, as to God, that worship which is due to the true God alone; for it is sufficient if he account him as God, by ascribing divine worship to him, though, in his mind, he may account him not to be the supreme God. It is no palliation of the crime, but an aggravation, if any one knowingly performs divine worship to him whom he knows not to be God.
13. And since Christ must be honored as the Father is, because he has been constituted by his Father KING and LORD, and has received all judgment, since every knee must bow to him, and since he is to be invoked as Mediator and the Head of his church, so that the church can pay this honor to no one except him, without incurring the crime of idolatry; therefore, the papists, who adore Mary, the angels, or holy men, and who invoke them as the donors and administrators of gifts, or as intercessors through their own merits, are guilty of the crime of idolatry.
14. Besides, when they adore the bread in the Lord’s supper, and receive and account the pope for that personage whom he boasts himself to be, they commit the sin of idolatry.