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

(51) O ye who believe! when ye meet the Unbelievers in hostile array, never turn your backs to them.

(52) It is not ye who slew them; it was Allah: when thou threwest (a handful of dust), it was not thy act, but Allah's: in order that He might test the believers by a gracious trial from Himself: for Allah is He Who heareth and knoweth (all things).

(53) That, and also because Allah is He Who makes feeble the plans and stratagem of the Unbelievers.

(54) (O Unbelievers!) if ye prayed for victory and judgment, now hath the judgment come to you: if ye desist (from wrong), it will be best for you: if ye return (to the attack), so shall We. Not the least good will your forces be to you even if they were multiplied: for verily Allah is with those who believe!

(55) Remember how the Unbelievers plotted against thee, to keep thee in bonds, or slay thee, or get thee out (of thy home). They plot and plan, and Allah too plans; but the best of planners is Allah.

(56) The Unbelievers spend their wealth to hinder (man) from the path of Allah, and so will they continue to spend; but in the end they will have (only) regrets and sighs; at length they will be overcome: and the Unbelievers will be gathered together to Hell;-

(57) Say to the Unbelievers, if (now) they desist (from Unbelief), their past would be forgiven them; but if they persist, the punishment of those before them is already (a matter of warning for them).

(58) If thou couldst see, when the angels take the souls of the Unbelievers (at death), (How) they smite their faces and their backs, (saying): "Taste the penalty of the blazing Fire-

(59) Let not the unbelievers think that they can get the better (of the godly): they will never frustrate (them).

(60) Should they intend to deceive thee,- verily Allah sufficeth thee: He it is That hath strengthened thee with His aid and with (the company of) the believers;