And We caused Isa, the son of Maryam, to follow in their (the earlier prophets) footsteps, confirming that which was before him of the Torah and We gave him the Injeel, in it was guidance and light, and a confirmation of that which was before it of the Torah and a guidance and an admonition for those who guard (against evil).
Christians should base the judgement of their disputes on the Injeel given to Isa (PBH).