The Prophet of Islam (PBUH) was asked:

Who are the most disliked people by God? The Prophet (PBUH) replied: Polytheists. The Prophet (PBUH) was asked again: Who else after them? The Prophet (PBUH) replied: (Those) cutting ties of relationship (with family and close relatives) [1]. It is narrated from Imam Sadeq (AS) who said: Luqman told his son: My dear son be good-tempered with all the people. If you do not have wealth to help your family and relatives, be nice and kind to them; because the one who is good-tempered, good people like him, and bad people stay away from him [1]. In another narration, Imam Sadeq (AS) said: Strengthen you ties with your family and close relatives even with a sip of water, and the best way to serve them is that, at least do not harass or bother them [3].

[1] Al-Kafi, Vol. 2, Page 290.

[2] Behrul Anwaar, Vol. 13, Page 420.

[3] Al-Kafi, Vol. 2, Page 151.

Source: en.shafaqna.com