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

(91) Say: "O ye men! If ye are in doubt as to my religion, (behold!) I worship not what ye worship, other than Allah! But I worship Allah - Who will take your souls (at death): I am commanded to be (in the ranks) of the believers,

(92) "And further (thus): 'set thy face towards religion with true piety, and never in any wise be of the Unbelievers;

(93) He it is Who created the heavens and the earth in six Days - and His Throne was over the waters - that He might try you, which of you is best in conduct. But if thou wert to say to them, "Ye shall indeed be raised up after death", the Unbelievers would be sure to say, "This is nothing but obvious sorcery!"

(94) But the chiefs of the Unbelievers among his people said: "We see (in) thee nothing but a man like ourselves: Nor do we see that any follow thee but the meanest among us, in judgment immature: Nor do we see in you (all) any merit above us: in fact we think ye are liars!"

(95) At length, behold! there came Our command, and the fountains of the earth gushed forth! We said: "Embark therein, of each kind two, male and female, and your family - except those against whom the word has already gone forth,- and the believers." but only a few believed with him.

(96) So the Ark floated with them on the waves (towering) like mountains, and Noah called out to his son, who had separated himself (from the rest): "O my son! embark with us, and be not with the unbelievers!"

(97) And the Unbelievers say: "Why is not a sign sent down to him from his Lord?" But thou art truly a warner, and to every people a guide.

(98) The Unbelievers say: "Why is not a sign sent down to him from his Lord?" Say: "Truly Allah leaveth, to stray, whom He will; But He guideth to Himself those who turn to Him in penitence,-

(99) If there were a Qur'an with which mountains were moved, or the earth were cloven asunder, or the dead were made to speak, (this would be the one!) But, truly, the command is with Allah in all things! Do not the believers know, that, had Allah (so) willed, He could have guided all mankind (to the right)? But the Unbelievers,- never will disaster cease to seize them for their (ill) deeds, or to settle close to their homes, until the promise of Allah come to pass, for, verily, Allah will not fail in His promise.

(100) Mocked were (many) messengers before thee: but I granted respite to the unbelievers, and finally I punished them: Then how (terrible) was my requital!