The word(s) "believer" appears 651 time(s) in 556 verse(s) in Quran in Mohsin Khan translation.

(141) O Prophet (Muhammad صلى الله عليه وسلم)! Urge the believers to fight. If there are twenty steadfast persons amongst you, they will overcome two hundreds, and if there be a hundred steadfast persons they will overcome a thousand of those who disbelieve, because they (the disbelievers) are people who do not understand.

(142) And those who believed, and emigrated and strove hard in the Cause of Allah (Al-Jihad), as well as those who gave (them) asylum and aid - these are the believers in truth, for them is forgiveness and Rizqun Karim (a generous provision i.e. Paradise).

(143) Freedom from (all) obligations (is declared) from Allah and His Messenger (صلى الله عليه وسلم) to those of the Mushrikun (polytheists, pagans, idolaters, disbelievers in the Oneness of Allah), with whom you made a treaty.

(144) So travel freely (O Mushrikun - See V.2:105) for four months (as you will) throughout the land, but know that you cannot escape (from the punishment of) Allah; and Allah will disgrace the disbelievers.

(145) And if anyone of the Mushrikun (polytheists, idolaters, pagans, disbelievers in the Oneness of Allah) seeks your protection, then grant him protection so that he may hear the Word of Allah (the Qur'an), and then escort him to where he can be secure, that is because they are men who know not.

(146) How can there be a covenant with Allah and with His Messenger for the Mushrikun (polytheists, idolaters, pagans, disbelievers in the Oneness of Allah) except those with whom you made a covenant near Al-Masjid-al-Haram (at Makkah)? So long as they are true to you, stand you true to them. Verily, Allah loves Al-Muttaqun (the pious - See V.2:2).

(147) With regard to a believer, they respect not the ties, either of kinship or of covenant! It is they who are the transgressors.

(148) Will you not fight a people who have violated their oaths (pagans of Makkah), and intended to expel the Messenger while they did attack you first? Do you fear them? Allah has more right that you should fear Him if you are believers.

(149) And remove the anger of their (believers') hearts. Allah accepts the repentance of whom He wills. Allah is All-Knowing, All-Wise.

(150) Do you think that you shall be left alone while Allah has not yet tested those among you who have striven hard and fought and have not taken Walijah [(Bitanah - helpers, advisors and consultants from disbelievers, pagans.) giving openly to them their secrets] besides Allah, and His Messenger, and the believers. Allah is Well-Acquainted with what you do.