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 and find peace in their hearts from the contemplation of God: Surely there is peace of heart in the contemplation of God!" 28 Those who have believed and done righteous deeds - a good state is theirs and a good return. 29 Thus have We raised thee [O Muhammad] as Our Apostle amidst a community [of unbelievers] before whose time [similar] communities have come and gone, so that thou might propound to them what We have revealed unto thee: for [in their ignorance] they deny the Most Gracious! Say: "He is my Sustainer. There is no deity save Him. In Him have I placed my trust, and unto Him is my recourse!" 30 Even if there were a Quran by which mountains could be set in motion, by which the earth could be rent asunder, or by which the dead could be made to speak [they would not believe in it]. Surely all things are subject to God's will. Are the faithful unaware that, had He pleased, God could have guided all mankind? Calamity shall not cease to strike those who deny the truth because of their misdeeds or to strike near their homes, until God's promise be fulfilled. God will not fail to keep His promise. 31