Two kinds , God's and man's. Man will get it right when he has God's kind of jealousy.
But man's jealousy come straight from the pit. It's petty, vindictive, it puts things out to stir up strife and cause division, pits ppl against each other, seeks to put down rather than build up, is basically a rejection of love, even though it uses it as an excuse.
Many a blatant crime has been commited by a jealous person, and many more are commited on a much more subversive level.
And like Lämmchen said, ppl often use other ppl to to 'get at' another and stir up jealousy. It doesn't always have to be open flirting, it's often more subtle. The withholding of affection, the lack of passion, the turning of attention away from the one, and towards another person or thing, ... These all stir jealousy and harm.
But love seeks no harm, and God's jealousy is so unlike man's. God loves us. He doesn't seek to harm us. He is jealous FOR us. He knows our turning our attention away from Him and towards idols, and sin, and man's type of jealousy and strife will only hurt us. He wants what's best for us, and His jealousy for us proves that out.
Not to keep us from love, but to keep us from harming ourselves and others.
Man's jealousy seeks to harm or get even, God's jealousy seeks to protect.
I'm grateful for God's jealousy, and the lessons He's been teaching me about this alot lately. He is such a good God. A good and jealous God.