The word(s) "believing" appears 60 time(s) in 45 verse(s) in Quran in Muhammad Pickthal translation.

(11) Then because of their breaking of their covenant, and their disbelieving in the revelations of Allah, and their slaying of the prophets wrongfully, and their saying: Our hearts are hardened - Nay, but Allah set a seal upon them for their disbelief, so that they believe not save a few -

(12) O Messenger! Make known that which hath been revealed unto thee from thy Lord, for if thou do it not, thou wilt not have conveyed His message. Allah will protect thee from mankind. Lo! Allah guideth not the disbelieving folk.

(13) Say O People of the Scripture! Ye have naught (of guidance) till ye observe the Torah and the Gospel and that which was revealed unto you from your Lord. That which is revealed unto thee (Muhammad) from thy Lord is certain to increase the contumacy and disbelief of many of them. But grieve not for the disbelieving folk.

(14) The chieftains of his people, who were disbelieving, said: Lo! we surely see thee in foolishness, and lo! we deem thee of the liars.

(15) But the chieftains of his people, who were disbelieving, said: If ye follow Shu'eyb, then truly ye shall be the losers.

(16) Postponement (of a sacred month) is only an excess of disbelief whereby those who disbelieve are misled; they allow it one year and forbid it (another) year, that they may make up the number of the months which Allah hath hallowed, so that they allow that which Allah hath forbidden. The evil of their deeds is made fairseeming unto them. Allah guideth not the disbelieving folk.

(17) Go, O my sons, and ascertain concerning Joseph and his brother, and despair not of the Spirit of Allah. Lo! none despaireth of the Spirit of Allah save disbelieving folk.

(18) That is because they have chosen the life of the world rather than the Hereafter, and because Allah guideth not the disbelieving folk.

(19) And naught prevented mankind from believing when the guidance came unto them save that they said: Hath Allah sent a mortal as (His) messenger?

(20) And naught hindereth mankind from believing when the guidance cometh unto them, and from asking forgiveness of their Lord unless (it be that they wish) that the judgment of the men of old should come upon them or (that) they should be confronted with the Doom.