Calling Christians Kafir Or Mushrik
Christians are not monotheists according to Quran’s definition of monotheism. However, Trinitarian Christians insist that God the Father, God the Son, and God the Holy Spirit share the same single essence, hence their belief is monotheistic. We can only discuss their misconception with them, point out their error, and discuss why their concept is polytheistic, however, we do not call them kafir or mushrik .