Allah informs true believers about genuine faith as follows:

[Adhere to the correct religion], turning in repentance to Him. Heed Him and establish prayer. Do not be among the idolaters. (Surat ar-Rum: 31)

Allah calls attention in another verse that the right way to follow is the way followed by prophets and morally upright people.

... but follow the Way of him who turns to Me. Then you will return to Me and I will inform you about the things you did. (Surah Luqman: 15)

Turning to Allah with heartfelt devotion means loving Him so much that one cannot refrain from faith, devotion and fidelity under any circumstances, and fears Him with awe. It is to have faith in Him with such reverence that one anxiously fears Him and ardently avoids losing His consent. Anyone believing in Allah in such a manner is sure to attain self-purification. One who believes and is so devoted to Allah performs prayers and other deeds to earn His consent sincerely. In reward for this, which is the basis of self-purification, true believers are "those who have faith and do right actions and humble themselves before their Lord." (Surah Hud: 23)

Allah instructed true believers to fulfill the orders and acts of worship prescribed in the Qur'an with total submission, sincerity and hearts purified for His sake. In a verse, it is related how Allah reminded Maryam (as) to submit to Him with heartfelt devotion: "O Maryam, worship your Lord devoutly: Prostrate yourself, and bow down (in prayer) with those who bow down." (Surah Al 'Imran: 43)

This is also stated by the Prophet (saas), who said:

"Goodness and comfort are for him who worships his Lord in a perfect manner and serves his Master sincerely."( Sahih Bukhari Hadith)

Allah also revealed the good news that those obeying Him with heartfelt devotion and fulfilling His orders with submission will be rewarded doubly:

But those of you who are obedient to Allah and His Messenger and act rightly will be given their reward twice over; and We have prepared generous provision for them. (Surat al-Ahzab: 31)

The characteristics of true believers, as mentioned in the verse below, are best exemplified in the prophets sent by Allah to warn people: "The steadfast, the truthful, the obedient, the givers, and those who seek forgiveness before dawn." (Surah Al 'Imran: 17)

The Qur'an contains many verses that emphasize the fact that prophets are men who turned to Allah with sincere devotion, His purified servants. Some examples are as follows:

Ibrahim was a community in himself, exemplary, obedient to Allah, a man of pure natural belief. He was not one of the idolaters. (Surat an-Nahl: 120)

And remember Our servants Ibrahim, Ishaq and Ya'qub, men of true strength and inner sight. We purified their sincerity through sincere remembrance of the Abode. (Surah Sad: 45-46)

Ibrahim was forbearing, compassionate, penitent. (Surah Hud: 75)

Mention Musa in the Book. He was truly sincere and was a Messenger and a Prophet. (Surah Maryam: 51)

And Maryam, the daughter of 'Imran, who guarded her chastity-We breathed Our Spirit into her and she confirmed the Words of her Lord and His Book and was one of the obedient. (Surat at-Tahrim: 12)