What is the ruling on living with a kaafir mother?

There is no reason why a son should not live with his kaafir mother, or her with him. That may be a means of her being guided to Islam, if the son treats her well and gives a good impression of Islam; keeping away from her may be a cause of her coming to Islam being delayed. 

The Muslim is enjoined to treat his parents well and honour them even if they are kuffaar. It is not permissible for a Muslim to disobey them or treat them badly in word and deed. But that does not mean that he should obey her in matters that are sinful or show approval of the kufr that she believes in. 

(a) Allaah says (interpretation of the meaning):

“And We have enjoined on man to be good and dutiful to his parents; but if they strive to make you join with Me (in worship) anything (as a partner) of which you have no knowledge, then obey them not. Unto Me is your return and I shall tell you what you used to do”

[al-‘Ankaboot 29:8]

(b) And Allaah says (interpretation of the meaning):

“But if they (both) strive with you to make you join in worship with Me others that of which you have no knowledge, then obey them not; but behave with them in the world kindly, and follow the path of him who turns to Me in repentance and in obedience. Then to Me will be your return, and I shall tell you what you used to do”

[Luqmaan 31:15] 

(c) It was narrated that Asma’ bint Abi Bakr (may Allaah be pleased with her) said: My mother came to me at the time of the Messenger of Allaah (peace and blessings of Allaah be upon him), and she was a mushrik. I asked the Messenger of Allaah (peace and blessings of Allaah be upon him) about that, saying, “My mother has come to me and she wants to visit me; should I uphold the ties of kinship with her?” He said, “Yes, uphold the ties of kinship with your mother.”

(Narrated by al-Bukhaari, 2477; Muslim, 1003) 

(d) It was narrated from Sa’d ibn Abi Waqqaas that a verse of Qur’aan was revealed concerning him. He said: Umm Sa’d swore that she should never speak to him until he gave up his religion, and she would never eat or drink. She said, “You claim that Allaah commands you to honour your parents, and I am your mother, and I am telling you to do this.” He said, She stayed like that for three days, until exhaustion overtook her, then one of her sons, whose name was ‘Amaarah, got up and gave her some water, and she started to pray against Sa’d. Then Allaah revealed Qur’aan (interpretation of the meaning):

“And We have enjoined on man to be good and dutiful to his parents; but if they strive to make you join with Me (in worship) anything (as a partner…”

[al-‘Ankaboot 29:8]

And He said (interpretation of the meaning): 

“…but behave with them in the world kindly…”

[Luqmaan 31:15] 

Narrated by Muslim, 1748. 

(e) There follows a fatwa from Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him) regarding the issue of obeying parents with regard to shaving the beard:

Question: Regarding obeying your father with regard to shaving the beard. 

The Shaykh replied: 

It is not permissible for you to obey your father in shaving the beard, rather you must let it grow, because the Prophet (peace and blessings of Allaah be upon him) said: “Trim the moustache and let the beard grow; be different from the mushrikeen.” And he (peace and blessings of Allaah be upon him) said: “Obedience is only with regard to that which is good and proper.”

Letting the beard grow is obligatory, not just Sunnah, according to fiqhi terminology, because the Messenger of Allaah (peace and blessings of Allaah be upon him) commanded that, and the basic principle is that a command is obligatory.

          Majmoo’ Fataawa al-Shaykh Ibn Baaz, 8/377-378 

See also the answer to question no. 5053 and 6401. 

And Allaah knows best.