And whoever acts hostilely to the Messenger after that guidance has become manifest to him, and follows other than the way of the believers, We will turn him to that to which he has (himself) turned and make him enter hell; and it is an evil resort.

And certainly Allah made a covenant with the children of Israel, and We raised up among them twelve chieftains; and Allah said: Surely I am with you; if you keep up prayer and pay the poor-rate and believe in My messengers and assist them and offer to Allah a goodly gift, I will most certainly cover your evil deeds, and I will most certainly cause you to enter into gardens beneath which rivers flow, but whoever disbelieves from among you after that, he indeed shall lose the right way.

And do not make your oaths a means of deceit between you, lest a foot should slip after its stability and you should taste evil because you turned away from Allah's way and grievous punishment be your (lot).