Some people raise objection, due to their ignorance, that why Shaykh-ul-Islam Dr Muhammad Tahir-ul-Qadri called the People of the Book "Believers"? This is just lack of knowledge. You'll find here that there are many scholars who called the People of the Book "Believers". They all called them Believers in terminology, not in the sense of Muslim faithful. So objectors should think over their standpoint and correct them for the sake of Allah's Din.