I have often been told that a little bit of jealousy is actually good, as it confirms that you have 'true' feelings for the person. I do not believe this to be the truth. Indeed, I would go so far as to argue that jealousy and love are antithetical and that the presence of jealousy shows a block in expressing full love for another. To argue this point I would take a look at the nature of jealousy and the nature of love.
What is jealousy? A quick search will tell you that "Jealousy is the state of fear or suspicion about losing something or someone important" (Wikipedia). While this is a reasonable definition, it fails to explain the maddening and persistent nature of jealousy in action. I am going to suggest that Jealousy is so maddening because what we are experiencing is a direct threat to the very sense of self of the afflicted individual.
We often experience falling in love as a melding or collapse of ego boundaries for both individuals. You feel like the other completes you. You may feel compelled to write a son about how much you need the other or how terrible life is when they are not there. You feel like your lover is indeed part of you. This can be though of as "co-ownership" of each other but I believe it goes deeper by creating a sense of co-identity.
As we know from psych 101, one of the primary fears of human existence is rooted in the uncertainty of self realness. Throughout life individuals develop functional methods for validating that they are real and/or valid as a person. Falling in love is a very powerful way to validate self. The feeling of filling a need in another and being an integral part of a "relationship" is a powerful validation saying "Yes, you are worthy, you are real!"
Now imagine that a persons needs are filled by someone else. All that validation comes crashing down. Jealousy is so strong because it cuts away at the systems developed to validate self-hood. Jealousy is indeed the fear of loosing something important but it is not the person or object of desire (you can never really 'have' someone). Jealousy is the fear of loosing the manufactured idea of self which derives it's realness from filling a real need in another person.
So, now we ask, what is love? I will refer to (my favorite) M. Scott Peck definition of love as "The will to extend one’s self for the purpose of nurturing one’s own or an other's spiritual (personal) growth." This definition highlights the incongruity of love with jealousy. What is key is that Jealousy only shows up in particular types of relationships: where one person is filling something lacking in the other (which causes the egoic collapse). If this is the dynamic, the relationship will keep each individual from growing in the areas where they need to grow. Instead of nurturing full 360 degree personal growth, they rely on the other to fill certain gaps. Jealousy is the product of a relational structure which blocks personal growth and hence the expression of genuine love.
Fortunately, this is not the only type of relationship structure. One can also approach a relationship with an energetic fullness which is eager to grow. In this case, each person is a reflection of the dynamic fullness in the other, rather than a patch for what is lacking. We are often attracted to people who embody what we lack in ourselves, but instead of attempting to integrate that person into our identity or sense of self, we can enjoy learning about ourselves through appreciating that expression in another. As we learn to understand that expression in another we begin to see it in ourselves. In this way, intimacy and openness is a very powerful tool for personal growth.
Jealousy is not part of love but an indication that the relationship is not fully loving. Jealousy can, however, be very useful. If we feel jealous, it is an indication that the ego has attempted to latch onto that person as validation of self. Jealousy is thus a sign to take a step back and re-evaluate how we are relating to that person who wish to love fully.
*I am sure these same thoughts have been articulated more eloquently and succinctly by many people before me. This is how it is coming up for me now as I learn from my teachers and peers and lovers.
