Pakistan has become conservative and intolerant society in recent decades.In past,we have many bureacrates who were not religious and even some were openly atheist.Foreign minister of Pakistan in 1962, Mr. Abdul Qadir was self-declared atheist.Alchol was banned in 1974.

Religion is personal matter.It has and should nothing to do with job.In CSS,you are dealing with highly educated panel.so it will not make a difference here that whether you are an atheist or mullah.But if you said something about your views in public they might not understand you and probably kill you.The case of Mashal khan is classic example.