Greeting the Shi’ah first
Question

                What is the ruling on greeting a Shi’i first with salaam? Especially since I mix with them a great deal and they do not proclaim their beliefs openly or slander (the Sahaabah) etc.
Praise be to Allah.
    What we say about interacting with the Shi’ah depends on the 
    situation. The innovated beliefs of the Shi’ah vary. If it is something that 
    does not put them beyond the pale of Islam, but is rather regarded as 
    drifting away from the right path, such as their claiming to be devoted to 
    Ahl al-Bayt (the family of the Prophet  (peace and blessings of Allaah 
    be upon him)), then it is permissible to greet them first, because they are 
    Muslims who have committed acts of innovation and sin that do not put them 
    beyond the pale of Islam, and we have to advise them and direct them towards 
    the Sunnah and the truth, and warn them against innovation and sin. If they 
    follow right guidance and accept advice, then praise be to Allaah, for this 
    is what we want. But if they persist in following innovation, then they 
    should be forsaken until they repent to Allaah and give up their innovations 
    and evil ways, because this is a kind of punishment for them. If something 
    good can be achieved by means of this forsaking, or something bad warded 
    off, then it is prescribed in sharee’ah, but if this forsaking will result 
    in something that will increase the evil caused by their innovations, then 
    it is not prescribed. 

    If you think that not forsaking them will serve a greater 
    interest and that mixing with them and advising them is more useful in 
    opening their hearts to true religion, then there is nothing wrong with not 
    forsaking them, because the aim behind forsaking them is to direct them to 
    the right way and to make them feel that we do not approve of their ways, so 
    that they may come back to true Islam.

    If forsaking them will harm the Muslims’ interests and make 
    them cling more firmly to their false ways and put them off the truth, then 
    it is better not to do that, just as the Prophet  (peace and blessings 
    of Allaah be upon him) did not forsake ‘Abd-Allaah ibn Ubayy ibn Salool, the 
    leader of the hypocrites, because not forsaking him was more in the 
    interests of the Muslims. 

    But if their bid’ah constitutes kufr, such as cursing the 
    Sahaabah and exaggerating about ‘Ali and Faatimah and al-Hasan and al-Husayn 
    (may Allaah be pleased with them), and they pray to them and seek their help 
    and ask them for support and so on, or their belief that they have knowledge 
    of the unseen etc, which means that they are beyond the pale of Islam, then 
    in this case it is not permissible to greet them first or to befriend them 
    or to eat meat slaughtered by them. Rather we must hate them and disavow 
    ourselves of them, until they believe in Allaah alone, because in this case 
    they are kaafirs and apostates. See Majmoo’ Fataawa Shaykh al-Islam, 
    28/216-217; Majmoo’ Fataawa Ibn Baaz, 4/262-263 
It should be noted here 
    that it is not permissible to greet a kaafir first in general terms, such as 
    saying Ahlan wa sahlan (welcome) and so on, because that involves honouring 
    them and venerating them, and the Muslim is higher in status before Allaah, 
    so we should not greet them first. But if they say that to us then we may 
    greet them in the same manner as they greeted us, because Islam is the 
    religion of justice that came to give each person his rights. 

    Al-Majmoo’ al-Thameen min Fataawa Ibn ‘Uthaymeen, 
    1/48 

    See also question no. 
    10843 

    And Allaah is the source of strength.