The word(s) "believed" appears 58 time(s) in 54 verse(s) in Quran in Abdullah Yusuf Ali translation.

(41) (Being) those who have believed in Our Signs and bowed (their wills to Ours) in Islam.

(42) Then, as to those who believed and did righteous deeds, their Lord will admit them to His Mercy that will be the achievement for all to see.

(43) Say: "See ye? If (this teaching) be from Allah, and ye reject it, and a witness from among the Children of Israel testifies to its similarity (with earlier scripture), and has believed while ye are arrogant, (how unjust ye are!) truly, Allah guides not a people unjust."

(44) O ye who believe! Let not some men among you laugh at others: It may be that the (latter) are better than the (former): Nor let some women laugh at others: It may be that the (latter are better than the (former): Nor defame nor be sarcastic to each other, nor call each other by (offensive) nicknames: Ill-seeming is a name connoting wickedness, (to be used of one) after he has believed: And those who do not desist are (indeed) doing wrong.

(45) Only those are Believers who have believed in Allah and His Messenger, and have never since doubted, but have striven with their belongings and their persons in the Cause of Allah: Such are the sincere ones.

(46) Then, in their wake, We followed them up with (others of) Our messengers: We sent after them Jesus the son of Mary, and bestowed on him the Gospel; and We ordained in the hearts of those who followed him Compassion and Mercy. But the Monasticism which they invented for themselves, We did not prescribe for them: (We commanded) only the seeking for the Good Pleasure of Allah; but that they did not foster as they should have done. Yet We bestowed, on those among them who believed, their (due) reward, but many of them are rebellious transgressors.

(47) And those who came after them say: "Our Lord! Forgive us, and our brethren who came before us into the Faith, and leave not, in our hearts, rancour (or sense of injury) against those who have believed. Our Lord! Thou art indeed Full of Kindness, Most Merciful."

(48) O ye who believe! Be ye helpers of Allah: As said Jesus the son of Mary to the Disciples, "Who will be my helpers to (the work of) Allah?" Said the disciples, "We are Allah's helpers!" then a portion of the Children of Israel believed, and a portion disbelieved: But We gave power to those who believed, against their enemies, and they became the ones that prevailed.

(49) That is because they believed, then they rejected Faith: So a seal was set on their hearts: therefore they understand not.

(50) Allah has prepared for them a severe Punishment (in the Hereafter). Therefore fear Allah, O ye men of understanding - who have believed!- for Allah hath indeed sent down to you a Message,-