ANSWER: There is a proper sort of love and an improper love. We generally think that all love is good, but what about excessive self-love? For example, Paul foretold that men would become lovers of themselves, lovers of money and pleasures. Jesus once said that whoever becomes his follower and does not hate his father and mother and wife and children and brother and sister and even his own soul, cannot be his disciple. Of course, Jesus was not advocating hate, but merely stressing the point that a Christian cannot love his family so much that we neglect our obligations to serve Christ. We must love God and Jesus more.
Just as there is a proper and improper love, so too, there is a proper and improper sort of jealousy. It would seem that love and jealousy are inseparable. Jealousy between marriage mates is proper. It is actually an expression of love and the expectation that each rightly reserves their affections exclusively for the other. If one mate were to flirt with someone to whom they were not married, or worse, be unfaithful, would that not be a cause of offense and jealousy for their mate? True, there can be a toxic sort of jealousy even within marriage, which we can attribute to our imperfect condition, but for the most part jealousy between marriage mates is healthy. In fact, if jealousy did not exist in a marriage it might be an indication of a lack of love on the part of one or both mates!
As you’re no doubt aware God even uses the human marriage arrangement and the heartbreak that adultery brings to illustrate his own relationship with his people. For example, in the prophecy of Hosea Jehovah compared Israel to a cheating wife. (See chapter 22: Hosea)
Obviously, when it comes to God he exhibits a proper sort of jealousy. In what way? Jehovah is jealous in the sense that he does not want to share our worship with another so-called god or object of veneration. In Isaiah Jehovah stated that he would not share his glory with anyone else nor allow his praise to go to graven images.
It is not that God is selfish. God does not covet something that someone else possesses. God merely wishes to receive that which belongs to him. It is perfectly natural and proper for all to worship Jehovah. It is actually harmful and degrading for us to worship anyone or anything other than the true God. He created all intelligent creatures so that they could worship and praise them. And why shouldn’t we, he is our Creator?
When you think about it, it would be a terrible thing if Jehovah were not jealous. Just think if God didn’t care, if allowed us to go our own way and worship sticks and stones, or whatever, and he made no attempt to save us for himself. Where would we be then?