What is the refutation to the claim made by some Christians that parts of the Quran are taken from the Gospel and the rest is fabricated?

This claim is false, and there is a vast difference between the Qur'an and the distorted Gospel in terms of content and style. The claimant must present proof, but the bankrupt resorts to hurling baseless accusations, just as the disbelievers among the Arabs did concerning the Qur'an, saying: "Tales of the ancients which he has written down, and they are dictated to him morning and evening." The proofs of the distortion of the Torah and the Gospel and the authenticity of the Qur'an have been clarified in previous fatwas. It suffices for a Muslim to respond to them with Allah's challenge to them: "And if you are in doubt about what We have sent down upon Our servant, then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful." And they will never do so.