And do not believe except in one who follows your religion. . .
This may refer to the beginning of a command from God (سبحانه) to the Muslims. The allusion in it is that you should not associate on intimate terms with opponents, nor divulge your secrets to outsiders.
Say: “True guidance is God's guidance-that anyone should be given the like of what you have been given, or that they should dispute with you before your Lord.” Say: “surely bounty is in God's hand;
He is the One who singles out whom He will for the lights of instruction and singles out whom He will for abandonment and deprivation.
He gives it to whomever He will; God is Embracing, Knowing.