The Women - 4:113
Had it not been for Allah´s grace and mercy upon you, a group of them would have led you astray. They can only mislead themselves; they can do you no harm. Allah sent down to you the Book and wisdom and taught you what you did not know. Allah´s favor towards you is great.
Fortified believer:
The Cave/18:14
"When they got up, We had made their hearts firm: "Our Lord is the Lord of the heavens and the earth. We shall have no gods besides Him. Otherwise, we would have spoken a false word."