Quran 3.137-140
Systems have passed away before you. Do but travel in the land and see the nature of the consequence for those who did deny (the messengers). This is a declaration for mankind, a guidance and an admonition unto those who ward off (evil) Faint not nor grieve, for ye will overcome them if ye are (indeed) believers. If ye have received a blow, the (disbelieving) people have received a blow the like thereof. These are (only) the vicissitudes which We cause to follow one another for mankind, to the end that Allah may know those who believe and may choose witnesses from among you; and Allah loveth not wrong-doers.