Inter-religious and inter-cultural relationship is one of the most significant subject of the present-day. Getting knowledge with regard to the historical, cultural and theological background of the problem might contribute to the solution of the question. In this framework, against the the challenges towards Islam from differend religious and cultural quarters, one of the Muslim theological defence is evaluated. In the study, Mutezilî Qadı Abdbulcabbar?s theological critiques with regard to Christian beliefs and rituals are investigated. His main conviction on this issue was that Christianity had been subject to change under the influence of other nations, especially of the Greeks.