Al-Ma'idah 5:51

۞يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ لَا تَتَّخِذُواْ ٱلۡيَهُودَ وَٱلنَّصَٰرَىٰٓ أَوۡلِيَآءَۘ بَعۡضُهُمۡ أَوۡلِيَآءُ بَعۡضٖۚ وَمَن يَتَوَلَّهُم مِّنكُمۡ فَإِنَّهُۥ مِنۡهُمۡۗ إِنَّ ٱللَّهَ لَا يَهۡدِي ٱلۡقَوۡمَ ٱلظَّـٰلِمِينَ 51

O you who have believed, do not take the Jews and the Christians as allies. They are [in fact] allies of one another. And whoever is an ally to them among you - then indeed, he is [one] of them. Indeed, Allah guides not the wrongdoing people