The word(s) "doubt" appears 83 time(s) in 77 verse(s) in Quran in Mohsin Khan translation.

(61) Verily they are in doubt concerning the Meeting with their Lord? (i.e. Resurrection after their death, and their return to their Lord). Verily! He it is Who is surrounding all things!

(62) And thus We have revealed to you (O Muhammad صلى الله عليه و سلم) a Qur'an in Arabic that you may warn the Mother of the Towns (Makkah) and all around it, and warn (them) of the Day of Assembling of which there is no doubt: when a party will be in Paradise (those who believed in Allah and followed what Allah's Messenger صلى الله عليه و سلم brought them) and a party in the blazing Fire (Hell) (those who disbelieved in Allah and followed not what Allah's Messenger صلى الله عليه و سلم brought them).

(63) And they divided not till after knowledge had come to them, through (selfish) transgression between themselves. And had it not been for a Word that went forth before from your Lord for an appointed term, the matter would have been settled between them. And verily, those who were made to inherit the Scripture [i.e. the Taurah (Torah) and the Injeel (Gospel)] after them (i.e. Jews and Christians) are in grave doubt concerning it (i.e. Allah's true religion - Islam or the Qur'an).

(64) And he ['Îsa (Jesus), son of Maryam (Mary)] shall be a known sign for (the coming of) the Hour (Day of Resurrection) [i.e. 'Isa's (Jesus) descent on the earth]. Therefore have no doubt concerning it (i.e. the Day of Resurrection). And follow Me (Allah) (i.e. be obedient to Allah and do what He orders you to do, O mankind)! This is the Straight Path (of Islamic Monotheism, leading to Allah and to His Paradise).

(65) Nay! They play about in doubt.

(66) "Verily, this is that whereof you used to doubt!"

(67) Say (to them): "Allah gives you life, then causes you to die, then He will assemble you on the Day of Resurrection about which there is no doubt. But most of mankind know not."

(68) And when it was said: "Verily, Allah's Promise is the truth, and there is no doubt about the coming of the Hour," you said: "We know not what is the Hour: we do not think it but as a conjecture, and we have no firm convincing belief (therein)."

(69) Only those are the believers who have believed in Allah and His Messenger, and afterward doubt not but strive with their wealth and their lives for the Cause of Allah. Those! They are the truthful.

(70) Were We then tired with the first creation? Nay, they are in confused doubt about a new creation (i.e. Resurrection).