Jealousy comes from a poverty of the heart and is essentially selfish. Jealousy is not born of love, but of pretty mindedness and dies simultaneously with the death of petty mindedness. Spiritual jealousy leads to advancement, while material jealousy leads to ruination and hatred. - Meher Baba
Always remember: the impressions of the Beloved, whether in worldly love or divine love, have their effect on you.
If you love “A” his impressions will attach to your mind without your knowing it; and if you become jealous of someone else, the impressions of both will affect you. That is, if Kim loves me, my impressions, which are divine, will affect her; and if you are jealous of her, then my infinite impressions, plus hers of love for me, will both affect you.
Therefore, jealousy in physical love is not good, while jealousy in spiritual love is good. Where there is love, there is jealousy. One automatically follows the other; there is no need to create it.
For example: when you love me, you want to possess me all the while. If I go away from you to another place or to some other lover, you suffer. (Lord Meher-p-1597)