The word(s) "sincere" appears 18 time(s) in 18 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) Say: Do you dispute with us about Allah, and He is our Lord and your Lord, and we shall have our deeds and you shall have your deeds, and we are sincere to Him.

(2) Except those who repent and amend and hold fast to Allah and are sincere in their religion to Allah, these are with the believers, and Allah will grant the believers a mighty reward.

(3) And he swore to them both: Most surely I am a sincere adviser to you.

(4) Say: My Lord has enjoined justice, and set upright your faces at every time of prayer and call on Him, being sincere to Him in obedience; as He brought you forth in the beginning, so shall you also return.

(5) It shall be no crime in the weak, nor in the sick, nor in those who do not find what they should spend (to stay behind), so long as they are sincere to Allah and His Apostle; there is no way (to blame) against the doers of good; and Allah is Forgiving, Merciful;

(6) He it is Who makes you travel by land and sea; until when you are in the ships, and they sail on with them in a pleasant breeze, and they rejoice, a violent wind overtakes them and the billows surge in on them from all sides, and they become certain that they are encompassed about, they pray to Allah, being sincere to Him in obedience: If Thou dost deliver us from this, we will most certainly be of the grateful ones.

(7) They said: O our father! what reason have you that you do not trust in us with respect to Yusuf? And most surely we are his sincere well-wishers:

(8) And certainly she made for him, and he would have made for her, were it not that he had seen the manifest evidence of his Lord; thus (it was) that We might turn away from him evil and indecency, surely he was one of Our sincere servants.

(9) So when they ride in the ships they call upon Allah, being sincerely obedient to Him, but when He brings them safe to the land, lo! they associate others (with Him);

(10) And when a wave like mountains covers them they call upon Allah, being sincere to Him in obedience, but when He brings them safe to the land, some of them follow the middle course; and none denies Our signs but every perfidious, ungrateful one.