Hadith No. 46 – Sahih al-Bukhari
The Prophet said, “Abusing a Muslim is Fusuq (an evil doing) and killing him is Kufr (disbelief).”
Narrated ‘Ubada bin As-Samit:
“Allah’s Apostle went out to inform the people about the (date of the) night of decree (Al-Qadr) but there happened a quarrel between two Muslim men. The Prophet said, “I came out to inform you about (the date of) the night of Al-Qadr, but as so and so and so and so quarrelled, its knowledge was taken away (I forgot it) and maybe it was better for you. Now look for it in the 7th, the 9th and the 5th (of the last 10 nights of the month of Ramadan).”
Fighting among believers doesn’t bring any good. Or we would’ve known the exact date of the night of Qadr. :)
Since all of us are believers, it’s not fitting for us to fight/abuse each other. May Allah protect us from this. Ameen.