Praise be to Allaah.
You should advise your friend to avoid making friends with the followers of bid’ah, especially extreme bid’ahs such as the Shi’ah and Raafidis, because being friends with them poses a danger to the Muslim’s religious and worldly interests. The danger to his religious interests involves the specious arguments that this Raafidi may present to him, causing him to doubt his religion, and the danger to his worldly interests involves the hatred that the Raafidi may feel towards Ahl al-Sunnah and he may strive to harm them in whatever ways he can.
There are ahaadeeth from the Prophet (peace and blessings of Allaah be upon him) which encourage us to choose our friends wisely, because of the influence that a friend may have on one’s attitude and religious commitment. These ahaadeeth include the following:
1 – It was narrated from Abu Sa’eed al-Khudri that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Do not keep company with anyone but a believer and do not let anyone eat your food but one who is pious.”
Narrated by al-Tirmidhi (2395)and Abu Dawood (4832); classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
2 – It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “A man will follow the way of his close friends, so let one of you look to whom he takes as a close friend.”
Narrated by al-Tirmidhi (2378) and Abu Dawood (4833). Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
Al-Khattaabi (may Allaah have mercy on him) said:
Do not take as a close friend anyone but one whose religious commitment and trustworthiness you are pleased with, for if you take him as a close friend, he will lead you to his religion and madhhab, so do not risk losing your religious commitment and expose yourself to danger by taking as a close friend one whose religious commitment and madhhab you are not pleased with. End quote.
Al-‘Azlah (p. 141)
Ibn ‘Abd al-Barr (may Allaah have mercy on him) said:
What this means – and Allaah knows best – is that a man will get used to what he sees of his friend’s actions. Hence he is commanded to make friends only with those whose actions are only good and permissible.
What this means is that a person should not mix with those who will make him do and believe things that are not praiseworthy. As for one with whom there is no such danger, there is nothing wrong with making friends with him. End quote.
Bahjat al-Majaalis (2/751).
The salaf said a great deal warning against making friends with the followers of bid’ah. For example:
1 – Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) narrated that Abu Yoosuf, the student of Abu Haneefah, said:
No one among Ahl al-Sunnah wa’l-Jamaa’ah should mix with anyone from among the people of whims and desires so that he makes friends with him and becomes his close confidante, lest he causes him to slip or causes others to slip because of this friendship.
Majmoo’ al-Fataawa (16/475)
2 – Abu Dawood al-Sijistaani (may Allaah have mercy on him) said:
I said to Abu ‘Abd-Allaah – Ahmad ibn Hanbal – I see a man from Ahl al-Sunnah with a man from the followers of innovation; should I stop speaking to him? He said: No, unless you know that the man whom you saw with him is a follower of innovation. If he stops speaking to him then speak to him, otherwise regard them as both being the same.
Tabaqaat al-Hanaabilah (1/160).
And Allaah knows best.