We may feel jealous of a successful person, but we are never jealous of the success of our own children, even though they are someone other than us. When we see ourselves in the other person, love comes naturally. And where there is love, there is no room for violence, hatred, enmity, or jealousy. Love is a substitute for everything, but there is no substitute for love. And when that love becomes divine, there is no further need to say anything!

— Swami Tejomayananda

Why is somebody glad when their own child is successful but jealous when somebody else experiences success? Isn’t it the feeling of ‘mine’ and ‘other’ that makes the difference? I am happy if ‘my’ child succeeds but jealous when some ‘other’ person is successful. If a child that is born out of you is your own, then we are all children of the same God and belong to one God. We are all born out of the same source, live in the same space, and in the end go back to the same source. Ultimately, we all dissolve into each other. Then where is the question of ‘mine’ and ‘not mine’?

Swami Vivekananda says,

If a beautiful picture belonging to another is burnt, a man does not generally become miserable; but when his own picture is burnt, how miserable he feels! Why? Both were beautiful pictures, perhaps copies of the same original; but in one case very much more misery is felt than in the other. It is because in one case he identifies himself with the picture, and not in the other. This ‘I and mine’ causes the whole misery.

— The Complete Works of Swami Vivekananda, vol. 1, p.101.

‘I’ and ‘mine’ and ‘other’ is the cause of all misery. Drop the feeling of ‘mine’ and ‘other’ and simply enjoy success, appreciate beauty wherever you find it, and you will become the embodiment of success and beauty! ‘I’ and ‘mine’ and ‘other’ is mere illusion. When you drop ‘I and mine’, the whole world becomes yours. Then what remains is the feeling of oneness, pure Love. And when there is Love, where is the room for violence, hatred, enmity, and jealousy?

See also, How to overcome jealousy, hatred, rivalry and ego consciousness?

The foolish blame love, without understanding the cause of pain; without knowing its conflict there is no transcending anguish. Without becoming aware of the source of conflict, craving, love brings pain. It is craving, not love, that creates dependence and all the sorrowful issues that arise out of it. it is craving in relationship that gives rise to uncertainty, not love; and this uncertainty breeds possessiveness, jealousy, fear. In this possessiveness, in this dependence, there is a false sense of unity which sustains and nourishes the temporary feeling of well being; but it is not love, for in it there is inward fear and suspicion. This outward stimulation of seeming oneness is parasitical, the living of the one on the other; it is not love for inwardly there is emptiness, loneliness and the need for dependence. Dependence breeds fear, not love. Without understanding craving is there not domination, oppression, taking the form of love? In relationship with the one or with the many, such love of power and dominance, with its submissiveness and acceptance, brings conflict, antagonism and sorrow. Having the seed of violence within oneself how can there be love? Having the seed of contradiction and uncertainty within oneself how can there be love? Love is beyond and above all these; it transcends sensuousness. Love is in itself eternal not dependent, not a result. In it there is mercy and generosity, forgiveness and compassion. With love, humility and gentleness come into being; without love they have no existence.

~ J. Krishnamurti, Ojai public talk, 18 June 1944

Well, here’s a suggestion from God himself!

O noble soul, open thy divine sight and regard and honour all beings as myself. Wise is he who looks with an equal eye upon all beings, seeing the one indwelling God in the hearts of all. He who meditates on my divine nature as present in every man becomes free from rivalry, from jealousy, from hatred, and from the consciousness of ego.

— Srimad Bhagavatam: The Wisdom of God,
Translated by Swami Prabhavananda. p. 303

Indeed, we all come from the same Source, we all ultimately go back to the same Source, and it’s the same Source or God who lives in the hearts of all beings and expresses Himself (or Herself or Itself) variously. The expressions themselves may be beautiful or distorted, but they keep changing, they are not fixed or eternal. God, the indweller,  outlives everything else, and He alone is the one eternal existence. When I recognize that the same God who lives and works through me lives in and works through the other person too, there is no question of hatred or jealousy in me. In fact, the other person is just another expression of myself, he/she is a mirror reflecting an aspect of myself and helps me discover myself. Only when we forget the oneness of existence and give too much importance to the differences, that’s when these negative emotions raise their head.

What happens when somebody else hates you and attacks you? When somebody attacks you, it’s reasonable for you to defend yourself, it’s perfectly okay to defend yourself. But even then, remembering the oneness of existence and acknowledging that the other person is the same as you in the core will prevent you from introducing further hatred. Further hatred on your part only escalates the problem, whereas when you look at the problem objectively, it always helps bring the situation under control and you can even help the other person overcome his hatred. This attitude has always worked for me. When I find myself having some problem with somebody, I internally acknowledge that we are both same in the core, it’s the same God who expresses himself through both of us differently. When I do this, the feeling of hatred immediately dies down even though the difference of opinion may persist for some time. Just that we both are looking at the same thing from different perspectives, the glasses might be of different colours, but it’s the same eye that looks through the different glasses. These differences are temporary, the clouds of misunderstanding has to pass, however dark they may be, however hopelessly overcast the conditions are, the clouds will disperse sooner or later, and suddenly, we find that the sun of understanding has always been shining resplendently. In fact, when you look at it from the perspective of the sun, the clouds have almost no existence at all!

Let me leave with you with a quote from Swami Vivekananda, who puts it in his own characteristically strong manner:

In one word, the ideal of Vedanta is to know man as he really is, and this is its message, that if you cannot worship your brother man, the manifested God, how can you worship a God who is unmanifested?