The Bee - 16:107
Because they preferred the life of this world to the Hereafter. Allah does not guide the disbelieving people.
Allah will not guide the disbelieving people: Related
The Thunder/13:11
(For each of them) there are those who watch him from in front of him and from behind him. They guard him by Allah´s command. Unless a community changes itself, Allah does not change their condition. And when Allah wills evil for a people, no power can stop it, nor do they have any protector except Him.