The unbelievers say, 'Why has a sign not been sent down upon him from his Lord?' Say: 'God leads astray whomsoever He will, and He guides to Him all who are penitent.' 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 Those who believe and work righteous works, for them is bliss and a happy resort. 29 Thus have we sent thee amongst a People before whom (long since) have (other) Peoples (gone and) passed away; in order that thou mightest rehearse unto them what We send down unto thee by inspiration; yet do they reject (Him), the Most Gracious! Say: "He is my Lord! There is no god but He! On Him is my trust, and to Him do I turn!" 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