There have been disagreements on certain matters among the noble Companions (Sahaba-e-Kiram, may Allah be pleased with them), but there was never any difference in their mutual respect. Who does not know that there was a severe disagreement among the noble Companions on the issue of the blood of Hazrat Uthman (may Allah be pleased with him), and even war took place because of it? But it was impossible that their disagreement would affect their mutual respect. Thus, right during the time of war, Hazrat Amir Muawiyah (may Allah be pleased with him) received a letter from the Christian Roman Empire, whose head was "Caesar". In it, it was written: "We have come to know that your leader (Hazrat Ali, may Allah be pleased with him) has not treated you well and is oppressing you. If you wish, we can send our army to help you." If we had been in your place, we would have called for an army to humiliate and degrade the opponent and defeat him. But what is worthy of listening to with full attention is the reply that Hazrat Amir Muawiyah (may Allah be pleased with him) gave to the Caesar of Rome: "O Christian dog! Do you want to take advantage of our disagreement?! Remember, if you look towards Hazrat Ali (may Allah be pleased with him) even with a crooked glance, then I will be the first one to become a soldier in Hazrat Ali's army and gouge your eye out." There are hundreds of such incidents; one has been quoted here as an example. The purpose is that for the unity of the Ummah, it is necessary that they respect and honor one another, do not let their disagreements exceed the limits, and deal with each other with kindness. (Read Incidents and Take a Lesson)