The word(s) "believer" appears 309 time(s) in 259 verse(s) in Quran in Abdullah Yusuf Ali translation.

(21) O ye who believe! When ye go abroad in the cause of Allah, investigate carefully, and say not to any one who offers you a salutation: "Thou art none of a believer!" Coveting the perishable goods of this life: with Allah are profits and spoils abundant. Even thus were ye yourselves before, till Allah conferred on you His favours: Therefore carefully investigate. For Allah is well aware of all that ye do.

(22) Not equal are those believers who sit (at home) and receive no hurt, and those who strive and fight in the cause of Allah with their goods and their persons. Allah hath granted a grade higher to those who strive and fight with their goods and persons than to those who sit (at home). Unto all (in Faith) Hath Allah promised good: But those who strive and fight Hath He distinguished above those who sit (at home) by a special reward,-

(23) When ye travel through the earth, there is no blame on you if ye shorten your prayers, for fear the Unbelievers May attack you: For the Unbelievers are unto you open enemies.

(24) When thou (O Messenger) art with them, and standest to lead them in prayer, Let one party of them stand up (in prayer) with thee, Taking their arms with them: When they finish their prostrations, let them Take their position in the rear. And let the other party come up which hath not yet prayed - and let them pray with thee, Taking all precaution, and bearing arms: the Unbelievers wish, if ye were negligent of your arms and your baggage, to assault you in a single rush. But there is no blame on you if ye put away your arms because of the inconvenience of rain or because ye are ill; but take (every) precaution for yourselves. For the Unbelievers Allah hath prepared a humiliating punishment.

(25) When ye pass (Congregational) prayers, celebrate Allah's praises, standing, sitting down, or lying down on your sides; but when ye are free from danger, set up Regular Prayers: For such prayers are enjoined on believers at stated times.

(26) Yea, to those who take for friends unbelievers rather than believers: is it honour they seek among them? Nay,- all honour is with Allah.

(27) (These are) the ones who wait and watch about you: if ye do gain a victory from Allah, they say: "Were we not with you?"- but if the unbelievers gain a success, they say (to them): "Did we not gain an advantage over you, and did we not guard you from the believers?" but Allah will judge betwixt you on the Day of Judgment. And never will Allah grant to the unbelievers a way (to triumphs) over the believers.

(28) O ye who believe! Take not for friends unbelievers rather than believers: Do ye wish to offer Allah an open proof against yourselves?

(29) Except for those who repent, mend (their lives) hold fast to Allah, and purify their religion as in Allah's sight: if so they will be (numbered) with the believers. And soon will Allah grant to the believers a reward of immense value.

(30) They are in truth (equally) unbelievers; and we have prepared for unbelievers a humiliating punishment.