The Response to Those Who Slander the Group and the Etiquette of Dialogue with the Opponent

Question:
The second part of his question says: But if they speak about my group, slander me, and accuse me, should I retaliate against them with two measures for every measure they used, because they have transgressed? And Allah commanded us to transgress against those who transgress against us, or what should I do? Because backbiting and talebearing have become widespread among the Islamic groups, and the responses between them are complete. Why is that, O Shaykh?

Answer:
Not with fasting, but with a like measure. Do not respond to them except with what they said. Rather, it is your right to use good manners and kind words. If they say, "You made a mistake in such and such an issue," tell him, "We did not make a mistake. We presented such and such evidence and such and such evidence. Investigate the matter properly, not with shouting or violence. Investigate the matter as if you are brothers. If the evidence becomes clear, the other party will return to the evidence. Shouting, measure for measure, no. But you tell them, "You did such and such, and you have no evidence. We said we have evidence for such and such. Come, let us discuss. We are brothers. We discuss and investigate: what is the evidence? What is the verse? What is the hadith that you have, that we have?"
Except, brothers, Muslims are brothers. We investigate. If the evidence appears with us, he joins us. And Allah is with you, but with you. Do not be partisan, and do not be partisan yourselves. But with good manners, with kind words, just as Allah said, "Argue with them" the disbelievers. He, the Exalted, said the Christians and the People of the Book. Who are the People of the Book?
The Jews and the Christians are disbelievers, and yet Allah says, "Do not argue with the People of the Book except in the best manner." The Christians, because violence drives people away from the truth. Violence causes people to disperse. But with kind words and good manners, not with two measures, is the correctness. It is by mentioning the truth, not by truth alone or by form, but with kind words, "My brother, such and such," and "My brother, such and such," and "My brother, Allah accepted such and such." The Messenger (peace and blessings be upon him) said such and such. The scholar so-and-so said such and such. Come, let us investigate the matter calmly. And if it does not become clear to me, I will not get angry early. Obstacles, three, two sessions, three, four, five. Do not get tired until the truth becomes clear. This is how the Salaf (may Allah be pleased with them) used to investigate and debate. Yes.