Al-Ma'idah' - 5:51

يَا أَيُّهَا الَّذِينَ آمَنُواْ لاَ تَتَّخِذُواْ الْيَهُودَ وَالنَّصَارَى أَوْلِيَاء بَعْضُهُمْ أَوْلِيَاء بَعْضٍ وَمَن يَتَوَلَّهُم مِّنكُمْ فَإِنَّهُ مِنْهُمْ إِنَّ اللّهَ لاَ يَهْدِي الْقَوْمَ الظَّالِمِينَ
[5:51]
O you who believe! do not take the Jews and the Christians for friends; they are friends of each other; and whoever amongst you takes them for a friend, then surely he is one of them; surely Allah does not guide the unjust people.
O ye who believe! take not the Jews and the Christians for your friends and protectors: They are but friends and protectors to each other. And he amongst you that turns to them (for friendship) is of them. Verily Allah guideth not a people unjust.
O ye who believe! Take not the Jews and the Christians for friends. They are friends one to another. He among you who taketh them for friends is (one) of them. Lo! Allah guideth not wrongdoing folk.