Allah forbids His believing servants from having Jews and Christians as friends, because they are the enemies of Islam and its people, may Allah curse them. Allah then states that they are friends of each other and He gives a warning threat to those who do this,
[وَمَن يَتَوَلَّهُمْ مِّنكُمْ فَإِنَّهُ مِنْهُمْ]
(And if any among you befriends them, then surely he is one of them.) Ibn Abi Hatim recorded that `Umar ordered Abu Musa Al-Ash`ari to send him on one sheet of balance the count of what he took in and what he spent. Abu Musa then had a Christian scribe, and he was able to comply with `Umar's demand. `Umar liked what he saw and exclaimed, "This scribe is proficient. Would you read in the Masjid a letter that came to us from Ash-Sham'' Abu Musa said, `He cannot.'' `Umar said, "Is he not pure'' Abu Musa said, "No, but he is Christian.'' Abu Musa said, "So `Umar admonished me and poked my thigh (with his finger), saying, `Drive him out (from Al-Madinah).' He then recited,
[يَـأَيُّهَا الَّذِينَ ءَامَنُواْ لاَ تَتَّخِذُواْ الْيَهُودَ وَالنَّصَـرَى أَوْلِيَآءَ]
(O you who believe! Take not the Jews and the Christians as friends...)'' Then he reported that `Abdullah bin `Utbah said, "Let one of you beware that he might be a Jew or a Christian, while unaware.'' The narrator of this statement said, "We thought that he was referring to the Ayah,
[يَـأَيُّهَا الَّذِينَ ءَامَنُواْ لاَ تَتَّخِذُواْ الْيَهُودَ وَالنَّصَـرَى أَوْلِيَآءَ]
(O you who believe! Take not the Jews and the Christians as friends, )'' Allah said,
[فَتَرَى الَّذِينَ فِى قُلُوبِهِم مَّرَضٌ]
(And you see those in whose hearts there is a disease...) A disease of doubt, hesitation and hypocrisy.
[يُسَـرِعُونَ فِيهِمْ]