Surah 43

Surah 43:65

"But the factions differed among themselves. Woe to those who have done evil because of the punishment of a painful Day!"

43.65 – But the factions differed among themselves
On the theme of differing and disagreement among Christians, see the comments at 98.4. It is true that the three large Christian groups in the Middle East during the seventh century (Byzantine, Nestorian, Monophysite) had differences among them. However, the Quran seems to imply that differences among Christians somehow negate the truth of the Gospel as well as Christian beliefs and practices. In fact, the three Christian groups were in agreement about the death of Jesus and the deity of Jesus – the main issues as far as the Quran is concerned. It was in describing the humanity of Jesus that differences emerged among the three Christian groups.

- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam