Quran on martyrs

And say not of those who are slain in God's cause, "They are dead": nay, they are alive, but you perceive it not.

And most certainly shall We try you by means of danger, hunger, loss of worldly goods, of lives and of [labour's] fruits. But give glad tidings unto those who persevere in adversity

Who, when calamity befalls them, say, "Verily, unto God do we belong and, verily, unto Him we shall return."
It is they upon whom their Sustainer's blessings and grace are bestowed, and it is they who are on the right path. (2:154-157)