Time and again we find examples in our holy books where Hashem shows His abhorrence of this heinous divide between Jew and Jew. But no matter what pain or suffering befall us, we continue on our suicidal path.
The answer to your question is obvious. You cannot be party to this abomination. Silence is consent. You must raise your voices and speak out. But be careful that you don’t do so with rancor, abuse or insult. Disparagement can only provoke further disparagement. So as difficult as it may be, make every effort to speak with patience and kindness. The formula you should bear in mind is “sad but not mad.”
But you cannot compromise – you cannot be tolerant of hatred between your children. This curse is poisoning your family and it must come to an end. Should your son and daughter-in-law continue to refuse to listen to reason, don’t give up. Try to reach them again and again. Knock on every door, but do not compromise on your demand to renounce hatred.
Obviously there are no guarantees, but I will tell you I had a great-great uncle who was a saintly sage and once counseled an obstinate man who refused to make peace. He talked his heart out to him, to no avail.
Some of his chassidim asked, “Why does the Rebbe expend his energy, his precious time, on this obnoxious person?” To which the Rebbe, my uncle, replied: “He may not listen today, he may not listen tomorrow, or even the day after, but eventually he will remember my words. We have a teaching, ‘Words that emanate from the heart must enter another’s heart.’ ”
May we behold the fulfillment of the prophecy of Malachi – which foretells the coming of Elijah who will unite the hearts of parents and children – speedily in our day.