The Bee - 16:9 It belongs to Allah to show the paths; some of them are crooked. Had He willed, He would have guided you all to the truth.
Related:
The Bee/16:93 Had Allah willed, He could have made you one people. But He leads astray whom He wills and guides whom He wills. Surely you will be questioned about what you used to do.

The Table Spread/5:48 We have sent down to you this Book, which confirms the previous Books and replaces them, as a comprehensive truth, so judge between them by what Allah has sent down to you. Do not leave the truth that has come to you and follow their whim. We have appointed for each of you a law and a method, and if Allah had willed, He would have made you all one people. But He tests you with what He has given you. Compete in good deeds. To Allah is the return of all of you. He will inform you of the matters on which you differ.

The Cattle/6:35 If their turning away is too much for you, know that even if you had the power to make a hole in the earth or a ladder in the sky, it would not profit you if you presented a miracle. Had Allah willed, He would have guided them. So do not be among the ignorant.

Prophet Hud/11:118 Had your Lord willed, He would have made the people one people. But they will always dispute (the truth).

The Thunder/13:31 Even if there were a Qur´an by which the mountains are moved, or the earth is torn asunder, or the dead are raised (they would not believe). All affairs are under the control of Allah. Have the believers not yet realized that if Allah willed, He could guide all mankind to the truth? Those who disbelieve will suffer a calamity, either upon their heads or upon their relatives, as a reward for what they have done, until Allah´s Word is fulfilled. Allah does not go back on His word.

The Bee/16:9 It belongs to Allah to show the paths; some of them are crooked. Had He willed, He would have guided you all to the truth.

Council/42:8 Had Allah willed, He could have made them one people. But He lets whom He wills into His mercy. The wrongdoers have no owner or helper.