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

(401) Except Iblis (Satan): he was proud and was one of the disbelievers.

(402) "Except Your chosen slaves amongst them (i.e. faithful, obedient, true believers of Islamic Monotheism)."

(403) Surely the religion (i.e. the worship and the obedience) is for Allah only. And those who take Auliya' (protectors, helpers, lords, gods) besides Him (say): "We worship them only that they may bring us near to Allah." Verily Allah will judge between them concerning that wherein they differ. Truly, Allah guides not him who is a liar, and a disbeliever.

(404) If you disbelieve, then verily, Allah is not in need of you; He likes not disbelief for His slaves. And if you are grateful (by being believers), He is pleased therewith for you. No bearer of burdens shall bear the burden of another. Then to your Lord is your return, and He will inform you what you used to do. Verily, He is the All-Knower of that which is in (men's) breasts.

(405) Then, who does more wrong than one who utters a lie against Allah, and denies the truth [this Qur'an, the Prophet (Muhammad صلى الله عليه وسلم) and the Islamic Monotheism] when it comes to him! Is there not in Hell an abode for the disbelievers?

(406) And he (Muhammad صلى الله عليه وسلم) who has brought the truth (this Qur'an and Islamic Monotheism) and (those who) believed therein (i.e. the true believers of Islamic Monotheism), those are Al-Muttaqun (the pious - See V.2:2).

(407) And verily, if you ask them: "Who created the heavens and the earth?" Surely they will say: "Allah (has created them)." Say: "Tell me then, the things that you invoke besides Allah - if Allah intended some harm for me, could they remove His harm? Or if He (Allah) intended some mercy for me, could they withhold His Mercy?" Say: "Sufficient for me is Allah; in Him those who trust (i.e. believers) must put their trust. "

(408) And those who did wrong (the polytheists and disbelievers in the Oneness of Allah), if they had all that is in earth and therewith as much again, they verily, would offer it to ransom themselves therewith on the Day of Resurrection from the evil torment; and there will become apparent to them from Allah what they had not been reckoning.

(409) Lest a person should say: "Alas, my grief that I was undutiful to Allah (i.e. I have not done what Allah has ordered me to do), and I was indeed among those who mocked [at the truth! i.e. La ilaha illallah (none has the right to be worshipped but Allah), the Qur'an, and Muhammad صلى الله عليه وسلم and at the faithful believers]

(410) Yes! Verily, there came to you My Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) and you denied them, and were proud and were among the disbelievers.