GOD IS A JEALOUS GOD - THAT JEALOUSY IS JUSTIFIED, ETHICAL AND HOLY
I) [Dt 6:13-15]
(Dt 6:13 NASB) "You shall fear only the LORD your God; and you shall worship Him and swear by His name.
(Dt 6:14 NASB) You shall not follow other gods, any of the gods of the peoples who surround you,
(Dt 6:14 NASB) for the LORD your God in the midst of you is a jealous God; otherwise the anger of the LORD your God will be kindled against you, and He will wipe you off the face of the earth."
[Bible Knowledge Commentary, Walvoord & Zuck, Eds., Victor Books, USA, 1988]:
"[Exodus] 6:13-19. When they would come into this prosperity the Israelites were to be all the more careful to fear Him (see comments on 4:10) and to serve Him. The command to swear (take... oaths) by the name of the Lord reinforces the instruction to fear Him, for one swears by the God he fears, that is, by the God under whom he is responsible to fulfill his oaths. If they would forget God (v. 12) they would almost certainly follow other gods, for God created people not only with the capacity to worship but with the need to worship. And this act of unfaithfulness would result in judgment since the Lord... is a jealous God (cf. 4:24; 5:9; 32:16, 21). This means He is zealous to protect what belongs to Him alone. Jealousy in this sense is ethically right. Jealousy in the sense of envy for another's possessions or privileges is, of course, wrong."
[Got Questions.org: "Why is God a jealous God?"]:
"It is important to understand how the word 'jealous' is used. Its use in Exodus 20:5 to describe God is different from how it is used to describe the sin of jealousy (Galatians 5:20).When we use the word "jealous,' we use it in the sense of being envious of someone who has something we do not have. A person might be jealous or envious of another person because he or she has a nice car or home (possessions). Or a person might be jealous or envious of another person because of some ability or skill that other person has (such as athletic abililty). Another example would be that one person might be jealous or envious of another because of his or her beauty.
In Exodus 20:5, it is not that God is jealous or envious because someone has something He wants or needs. Exodus 20:4-5 says, 'You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them, for I, the LORD your God, am a jealous God..." Notice that God is jealous when someone gives to another something that rightly belongs to Him.
In these verses, God is speaking of people making idols and bowing down and worshiping those idols instead of giving God the worship that belongs to Him alone. God is possessive of the worship and service that belong to Him. It is a sin (as God points out in this command) to worship or serve anything other than God. It is a sin when we desire, or we are envious, or we are jealous of someone because he has something that we do not have. It is a different use of the word 'jealous' when God says He is jealous. What He is jealous of belongs to Him, worship and service belong to Him alone, and are to be given to Him alone.
Perhaps a practical example will help us understand the difference. If a husband sees another man flirting with his wife, he is right to be jealous, for only he has the right to flirt with his wife. This type of jealousy is not sinful. Rather, it is entirely appropriate. Being jealous for something that God declares to belong to you is good and appropriate. Jealousy is a sin when it is a desire for something that does not belong to you. Worship, praise, honor, and adoration belong to God alone, for only He is truly worthy of it. Therefore, God is rightly jealous when worship, praise, honor or adoration is given to idols. This is precisely the jealousy the apostle Paul described in 2 Corinthians 11:2, 'I am jealous for you with a godly jealousy.' "