Referring to the disbelievers as brothers
Q: Praise be to Allah, we are Muslims, but we have a Christian brother. Is it permissible to eat and drink with him? Please advise us. May Allah reward you with the best!
The Muslim is the brother of the Muslim, not the Kafir. Even if they are biological brothers, yet, they are not brothers in religion whether this brother is a Jew, Christian, Magian, Communist, Qadiani or Pagan. The Kafirs (disbelievers) are not our brothers; rather, we have hostility and hatred between us and them, though we should treat them kindly.
If they are poor and not belligerent; there is nothing wrong with being kind to them if they are Dhimmy (protected non-Muslim living under Islamic rule) or Musta’minin (non-Muslims with a peace agreement permitting them to enter and stay temporarily in a Muslim country). It is permissible to treat them kindly if they are poor and call them to Islam.
Still, they are neither our brothers nor bosom friends, as we should hate them for the sake of Allah (Exalted be He) till they are guided. As previously mentioned, we should be kind to them, call them to the way of Allah (Exalted be He) and ask Him to grant them guidance, for all this is required.
On the other hand, if they are engaged in warfare with us, we should hate them for the sake of Allah, fight them, boycott them and never help them in anyway. Supporting them against Muslims is an act of Kufr (disbelief) and apostasy. Therefore, you should not take this Christian man as a friend or even eat with him. But, if it happened and you became obliged to be in his companionship as a housemate or guest, there is nothing wrong with sharing your food with him, provided that you do not make him a bosom friend or helper.
Rather, you should consider him as an enemy and hate him for the sake of Allah until he follows guidance. Again, you can eat with him if necessary or in case he is your guest or housemate without seeking his friendship or companionship. This is to avoid being drawn to his evil or becoming negligent in that which Allah (Exalted be He) has imposed on you as regards him. Allah is the One to be sought for help.
Fatwas of Nur `Ala Al-Darb>Volume 1>Chapter on `Aqidah>Chapter on Al-Wala’ wal-Bara’>Ruling on being kind to the Dhimmy and Musta’man