This expression has reference to the fact that Jehovah does not tolerate any rivalry, the worship of any other gods. The Hebrew word qan·naʼʹ is used only of God; it means “exacting exclusive devotion; jealous.”​—Ex 20:5, ftn; see JEALOUS, JEALOUSY.

God will not transfer to another the honor due himself. (Isa 42:8) To depart from exclusive devotion to him would incur the heat of His zealous anger. (De 4:24; 5:9; 6:15) Israel was regarded as being married to Jehovah. As a husband, Jehovah claimed exclusive devotion, loyalty, fidelity from Israel. He would be zealous, full of ardor in her behalf, in her defense. (Eze 36:5) Conversely, disobedience, going after other gods, would be adultery, thereby meriting Jehovah’s righteous anger and his jealousy for his own name.​—De 32:16, 21; Eze 16:38, 42.

What is the exclusive devotion that Jehovah requires from his servants?

The word “exclusive” is from the Latin exclusus, meaning “altogether shut out.” Devotion means  strong attachment and ardent love. Exclusive devotion, therefore, means keeping others out of, or excluded from, God’s position in our hearts and actions. Everyone and everything else stays outside this honored position that only he can hold.

Jehovah God Tolerates No Rivalry. Exclusive devotion is demanded by Jehovah in the second of the “Ten Words” or Ten Commandments written by the finger of God: “I am Jehovah your God . . . You must never have any other gods against my face [or, “any other gods in defiance of me”]. . . . because I Jehovah your God am a God exacting exclusive devotion.” (De 5:6-9) At Exodus 34:14 the French Drioux Version (1884) says: “God wants to be loved uniquely,” that is, in a class by himself, singularly. Jesus supported this view when he spoke to a Jew who tried to test him. (Mt 22:37) Jehovah was both God and King of Israel, Head of religion and of State. Therefore, for an Israelite to break the first and second commandments by serving other gods meant that he was committing lèse-majesté, or treason, the highest of crimes, meriting the heaviest punishment. On one occasion Israel was engaging in the worship of a false god as well as practicing immorality and, because of Jehovah’s full insistence on exclusive devotion, was about to be exterminated. But because Phinehas, Aaron’s grandson, took swift action in “tolerating no rivalry” toward Jehovah, Israel was saved.​—Nu 25:11.

Jehovah’s purpose in restoring his people after the Babylonian exile was for his name’s sake. (Eze 39:25-28) At Exodus 34:14, Fenton’s translation reads: “The EVER-LIVING is jealous of HIS NAME.” Since he is jealous of his name or exclusively devoted to it, he did not tolerate any rivalry by the name of any other god among his people.

Master and Slave Relationship. Exclusive devotion also suggests the relation between master and slave. Jehovah as Creator is Owner and Master. He is God by reason of his creatorship; it is his right to receive exclusive devotion from his created subjects, and they must do his will. The right-minded person, on learning about Jehovah and appreciating his relationship with God, will voluntarily render exclusive devotion from the heart, which is what Jehovah desires. Mere formal devotion or worship he hates. (Mt 15:8, 9) This relationship and the freewill devotion that Jehovah desires were illustrated in the Mosaic Law. A Hebrew slave was let go free in his seventh year of servitude. “But if the slave should insistently say, ‘I really love my master, my wife and my sons; I do not want to go out as one set free,’ then his master must bring him near to the true God and must bring him up against the door or the doorpost; and his master must pierce his ear through with an awl, and he must be his slave to time indefinite.” (Ex 21:2, 5, 6) Paul spoke to non-Jews in the Thessalonian congregation about the voluntary shift of devotion made when they became Christians. They ceased being slaves to idols and began “to slave for a living and true God.”​—1Th 1:9.

Jesus’ Exclusive Devotion to God. As shown in Philippians 2:5-8, both when he was in heaven and when he was on earth, Jesus appreciated the exclusive position of his Father and rendered him exclusive devotion. Jesus pointed out that the most important commandment in the Law demanded wholehearted love of God. (Mt 22:37) Moreover, Jesus manifested exclusive devotion to Jehovah’s name and emphasized the fact that his disciples should have the same attitude. In the prayer he taught his disciples, he started off with the words, “Our Father in the heavens, let your name be sanctified.” (Mt 6:9) This devotion in Jesus was coupled with burning zeal, as manifested at his cleansing of the temple, where he fulfilled the prophecy, “The zeal for your house will eat me up.” (Joh 2:17; Ps 69:9) Nowhere is Jesus’ exclusive devotion to his Father exemplified more than in what is written of him at 1 Corinthians 15:24-28, where it says that, after his heavenly Kingdom rule puts down all other authority and all enemies, he turns over the Kingdom to the Father and subjects himself to Him so that “God may be all things to everyone.”