Question: What is the reality of the mathab [school of thought] of the Raafidah and what is the ruling on dealing with them if they work with us in a school?
Answer: I see that you deal with them like how they deal with you, step by step due to Allah’s statement: “When you are greeted with a greeting, greet in return with what is better than it, or (at least) return it equally. Certainly, Allah is Ever a Careful Account Taker of all things” [9:86].
Questioner: What is the ruling if I see him making sujud on something?
Shaikh: Advise him.
Questioner: Should I return his Salam?
Answer: Yes, it is necessary if he gives you Salam that you respond to his Salam. Likewise if you and them exchange some decisions than there is no problem. However, like I said: it is necessary to observe the benefit.
[Taken from Liqaa al-Baab ul-Maftooh no. 220 found here:http://audio.islamweb.net/AUDIO/index.php?page=FullContent&audioid=112108&full=1]
Translated by Faisal ibn Abdul Qaadir ibn Hassan