and if allah please he would certainly make you a single nation but he causes to err whom he pleases and guides whom he pleases and most certainly you will be questioned as to what you did.
ولو شاء الله لجعلكم أمة واحدة ولكن يضل من يشاء ويهدي من يشاء ولتسألن عما كنتم تعملون