At Psalm 37:8 we read in part:
‘Don’t let jealousy move you to do wicked things.’
However, notice that the Greek word we’ve translated as jealously here is zelos, which is the same as the word that is spelled as zealously in English. This points to the fact that both English words (zealous and jealous) come from the same Greek root word, and they both have the same meaning in the Bible.
Of course, in English, these two words have very different meanings. For zeal is usually thought of as something good, something that all Christians should have (as in zeal for God and righteousness). While jealously is thought of as something that’s bad (as wanting things that belong to someone else).
Notice that God is spoken of in the Bible as being jealous over His Name or His position as God. So jealously isn’t always a bad thing, if we understand that it can imply the same thing as zeal.
Therefore, we can righteously have zeal for things that are ours and of which we are proud), or have unrighteous zeal (jealousy) for things that belong to others. So the same Greek word (zelos) may be correctly translated as zeal in one place, and as jealously in another, depending on the context.
Then, is it proper for a man to be jealous of his wife, or for a wife to be jealous of her husband? No, they should never be jealous of each other, but rather, for each other.
They shouldn’t want what the other has, but they should have a burning zeal for each other, because they belong to each other.
So, when one doesn’t want to lose the love of the other, that is zeal.
However, if a person is overly concerned over the actions of the other for no reason, that is wicked suspicion, not jealously.