وَمِنَ ٱلَّذِينَ قَالُوٓا۟ إِنَّا نَصَٰرَىٰٓ أَخَذْنَا مِيثَٰقَهُمْ فَنَسُوا۟ حَظًّا مِّمَّا ذُكِّرُوا۟ بِهِۦ فَأَغْرَيْنَا بَيْنَهُمُ ٱلْعَدَاوَةَ وَٱلْبَغْضَآءَ إِلَىٰ يَوْمِ ٱلْقِيَٰمَةِ ۚ وَسَوْفَ يُنَبِّئُهُمُ ٱللَّهُ بِمَا كَانُوا۟ يَصْنَعُونَ
3:56; 5:65.
Commentary:
After referring to the Jews in the preceding verses, the Quran here refers to the Christians, who had also fallen low owing to their ceasing to act on the commandments of God.
The words, We have caused enmity and hatred among them, either refer to the Christians and the Jews spoken of in the preceding verse or they refer to the Christians alone as understood by the present verse. In any case they embody a great prophecy to the truth of which the whole world is a witness. Unappeasable animosity, hatred and rivalry exist not only between Christians and Jews but also between the different sections of Christians themselves. This enmity and discord are a natural result of their rejection of Islam. The Holy Prophet, who had a universal mission, brought the Message of the oneness of all mankind. All nations of the world were invited to assemble under his banner and thus become welded into one nation and one people. But the People of the Book refused to accept him. So not only will Jews and Christians as well as the sections thereof continue to remain at loggerheads with each other, but the phantom of world-peace will also continue to elude humanity till men come to render allegiance to that Great and Noble Prophet whom God sent as "a mercy for all mankind".
The Arabic word یصنعون (have been doing) is generally used concerning works of art. The allusion is thus primarily to the works of art in which Christian nations were to excel and take pride.
This seems to be a reference to Jesus’s prophecy about the advent of the Holy Prophet (John, 16: 12, 13) which his followers deliberately ignored or upon which they vainly sought to put a wrong interpretation.