The word(s) "monotheism" appears 283 time(s) in 267 verse(s) in Quran in Mohsin Khan translation.

(41) And those who disbelieve are allies of one another, (and) if you (Muslims of the whole world collectively) do not do so [i.e. become allies, as one united block under one Khalifah (a chief Muslim ruler for the whole Muslim world) to make victorious Allah's religion of Islamic monotheism], there will be Fitnah (wars, battles, polytheism) and oppression on the earth, and a great mischief and corruption (appearance of polytheism).

(42) Those who believed (in the Oneness of Allah - Islamic monotheism) and emigrated and strove hard and fought in Allah's Cause with their wealth and their lives are far higher in degree with Allah. They are the successful.

(43) They (the disbelievers, the Jews and the Christians) want to extinguish Allah's Light (with which Muhammad صلى الله عليه وسلم has been sent - Islamic monotheism) with their mouths, but Allah will not allow except that His Light should be perfected even though the Kafirun (disbelievers) hate (it).

(44) O you who believe! Verily, there are many of the (Jewish) rabbis and the (Christian) monks who devour the wealth of mankind in falsehood, and hinder (them) from the Way of Allah (i.e. Allah's religion of Islamic monotheism). And those who hoard up gold and silver [Al-Kanz: the money, the Zakat of which has not been paid] and spend them not in the Way of Allah, announce unto them a painful torment.

(45) The hypocrites, men and women, are one from another; they enjoin (on the people) Al-Munkar (i.e. disbelief and polytheism of all kinds and all that Islam has forbidden), and forbid (people) from Al-Ma'ruf (i.e. Islamic monotheism and all that Islam orders one to do), and they close their hands [from giving (spending in Allah's Cause) alms]. They have forgotten Allah, so He has forgotten them. Verily, the hypocrites are the Fasiqun (rebellious, disobedient to Allah).

(46) The believers, men and women, are Auliya' (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) Al-Ma'ruf (i.e. Islamic monotheism and all that Islam orders one to do), and forbid (people) from Al-Munkar (i.e. polytheism and disbelief of all kinds, and all that Islam has forbidden); they perform As-Salat (Iqamat-as-Salat), and give the Zakat, and obey Allah and His Messenger. Allah will have His Mercy on them. Surely Allah is All-Mighty, All-Wise.

(47) But the Messenger (Muhammad صلى الله عليه وسلم) and those who believed with him (in Islamic monotheism) strove hard and fought with their wealth and their lives (in Allah's Cause). Such are they for whom are the good things, and it is they who will be successful.

(48) (The believers whose lives Allah has purchased are) those who turn to Allah in repentance (from polytheism and hypocrisy, etc.), who worship (Him), who praise (Him), who fast (or go out in Allah's Cause), who bow down (in prayer), who prostrate themselves (in prayer), who enjoin (on people) Al-Ma'ruf (i.e. Islamic monotheism and all what Islam has ordained) and forbid (people) from Al-Munkar (i.e. disbelief, polytheism of all kinds and all that Islam has forbidden), and who observe the limits set by Allah (do all that Allah has ordained and abstain from all kinds of sins and evil deeds which Allah has forbidden). And give glad tidings to the believers.

(49) To Him is the return of all of you. The Promise of Allah is true. It is He Who begins the creation and then will repeat it, that He may reward with justice those who believed (in the Oneness of Allah - Islamic monotheism) and did deeds of righteousness. But those who disbelieved will have a drink of boiling fluids and painful torment because they used to disbelieve.

(50) Mankind were but one community (i.e. on one religion - Islamic monotheism), then they differed (later); and had not it been for a Word that went forth before from your Lord, it would have been settled between them regarding what they differed .