And those who disbelieved say, "Why has a sign not been sent down to him from his Lord?" Say, [O Muhammad], "Indeed, Allah leaves astray whom He wills and guides to Himself whoever turns back [to Him] - 27 Those who believe (in the Oneness of Allah - Islamic Monotheism), and whose hearts find rest in the remembrance of Allah, Verily, in the remembrance of Allah do hearts find rest. 28 The righteously striving believers will receive abundant blessings and the best eternal dwelling. 29 Thus have We sent you to a community before which [other] communities have passed on so you might recite to them that which We revealed to you, while they disbelieve in the Most Merciful. Say, "He is my Lord; there is no deity except Him. Upon Him I rely, and to Him is my return." 30 Yet even if [they should listen to] a [divine] discourse by which mountains could be moved, or the earth cleft asunder, or the dead made to speak - [they who are bent on denying the truth would still refuse to believe in it]! Nay, but God alone has the power to decide what shall be. Have, then, they who have attained to faith not yet come to know that, had God so willed; He would indeed have guided all mankind aright? But as for those who are bent on denying the truth - in result of their [evil] deeds, sudden calamities will always befall them or will alight close to their homes; [and this will continue] until God's promise [of resurrection] is fulfilled: verily, God never fails to fulfil His promise! 31