Q 1: I have two equally capable workers, one of them is a Muslim and the other is a Kafir (nonMuslim). I am asked to assess their work. Is it permissible for me to underestimate the Kafir because of his beliefs?
A: You must establish justice between them. However, it would be best to dismiss the Kafir, even if he is more efficient, as Muslim workers are more blessed, even if they are less efficient, let alone if they are equally capable. It was authentically reported from the Prophet (peace be upon him) that he advised expelling the Kafirs out of the Arabian Peninsula, so that there remains only one faith in it. May Allah grant us success!