Translation: [ Imam Abu-Hamed Al-Ghazali talked in detail about this topic. Below is a quotation from what he said on this topic taken from ' Ihya'a Ulum Al-Din (Revival of the Religious Sciences) '.
Translation: The four Ranks of Devoutness and their Signs
As to the First Rank, this is the devoutness of the just people. It means refraining from doing forbidden deeds that are categorized as absolutely unlawful. A person who commits any of these acts is called rebellious or disobedient.
The Second Rank comprises doubtful matters whose shunning is desirable, but not obligatory. For, the acts it is obligatory to shun are categorized as unlawful prohibitions. As to refraining from the doubtful matters whose shunning is disliked, this is the devoutness of the punctilious. An example of this is refraining from hunting incase the game had escaped from another hunter. This is a form of suspicion. As to the doubtful matters whose shunning is desirable but not obligatory, they include what the Messenger of Allah referred to in his Hadith:
Hadith
Narrated Hassan ibn Abu-Sinan: ' The Messenger of Allah said: " refrain from doing any action about which you have doubts and do only the things you have no doubts about. " We consider this forbiddance as a recommended prohibition.
It is narrated that Ibn Sireen left four thousand Dirhams to a partner because deep within he felt uneasy about them. However, scholars think that there is no harm in such matters. Thus, every affair that casts doubts in the heart of the Muslim, is judged according to this ruling.
As to the Third Rank, this is the devoutness of the pious people. This is confirmed by the following Hadith of the Messenger of Allah: " The servant does not attain the rank of the pious until he gives up a plainly lawful affair lest he should commit a doubtful affair. "
Omar said: ' We used to leave nine tenths of the lawful affairs lest we should do an unlawful affair. '
When Al-Hasan was a child he took a date from the dates that had been given in charity, the Prophet said to him: " Leave it.! Leave it! "
Someone who was attending a righteous person at the time of his death rattle said that the man asked the attendants to turn the lantern off because the fuel had become the property of his heirs.
Refraining from adorning oneself through fear that it should arouse pride in oneself is categorized as leaving a plainly lawful affair lest it should lead to a doubtful affair, as adorning oneself is lawful. It is known that most of the permissible affairs are liable to lead to forbidden ones. An example of this is filling one's stomach (especially that of a bachelor) with lawful food and drink, because this stirs sexual desire. Lust leads to thinking, thinking leads to gazing, and gazing leads to evil behavior. Another example is looking at the rich people's decorated houses. This is permissible, but it stirs in man covetousness to own the like of them. Such a desire may lead to earning money unlawfully.
The same applies to the permissible affairs if one does not behave moderately act cautiously, avoiding their harms, because this conduct is not risk-free.
This applies, a fortiori, to any thing done lustfully. For this reason, the righteous predecessors disliked wearing thin clothes. They said that he whose clothes are thin, his religion is " thin. " They did so [ i.e. avoided wearing thin clothes] out of fear lest the permissible affair should lead to an unlawful one.
The human soul desires both the permissible and the impermissible in the same degree. If it becomes accustomed to [ following its] lusts it becomes covetous. Thus devoutness entails leaving all of this. Thus, a Muslim is permitted to enjoy any lawful affair that does not comprise any actions that have been warned against. This is the third type of lawful affair.
As to the Fourth Rank, it is the devoutness of the truthful. The lawful to them is anything that does not comprise an act of disobedience, leads to an act of disobedience, or something that one is not driven to by an imminent or future purpose. One enjoys it for Allah's sake alone, to strengthen oneself to perform acts of worship, and to have good health to be able to do what pleases Allah.
This is the rank of the monotheists who have discarded the desires of their own basic selves. They are the ones who do their deeds solely for Allah's sake. This is why As-Seddeeq purposefully vomited milk (that was earned unlawfully by his slave), although he had drunken it without knowing that it was earned unlawfully, lest it he should gain strength from it. It was not obligatory on As-Seddeeq to vomit it, but removing illegally earned food from one's stomach is the devoutness of the truthful.
In brief, devoutness has a starting point i.e. refraining from what is forbidden by verdicts and this is the devoutness of the just people. Its end is the devoutness of the truthful i.e. refraining from whatever is not done just for the sake of Allah
, that was taken lustfully, through disliked means, or what was related to a disliked affair. There are in-between degrees. The more sternly one reckons his soul, the lighter his load will be on the Day of Judgment, the more quickly his passing on as-Sirat will be, and the more probable that the pan of his good deeds will outweigh the one with his evil deeds.
The degrees in the Hereafter will differ proportionally to the degrees of devoutness, as the degrees in Hellfire will differ proportionally to the degrees of unlawful deeds that one committed.
Knowing the reality about this, you have the choice. You have to be on guard as much as you possibly can, to be on the safest side. And peace be upon you. '
Well, is time now to see what Imam Al-Nawawi compiled on this subject.]
Translation: " O you who believe! Fear Allah (by doing all that He has ordered and by abstaining from all that He has forbidden) as He should be feared. (Obey Him, be thankful to Him, and remember Him always), and die not except in a state of Islam. " (3: 102) And
Translation: " So keep your duty to Allah and fear Him as much as you can. Listen and obey, and spend in charity, for this is better for yourselves. And whosoever is saved from his own covetousness then they are the successful ones. ** " (64: 16) And
Translation: " Then when they (the wives you have irrevocably divorced) are about to attain their appointed term, either take them back in a good manner or part with them in good manner. And take as witness two just persons from among you (Muslims) and establish the testimony for Allah. That will be an admonition given to him who believes in Allah and the Last Day. And whosoever fears Allah and keeps his duty to Him, He will make a way for him to get out (from every difficulty), * And He will provide him from (sources) that he could never imagine. And whosoever puts his trust in Allah, then Allah will suffice him. Verily, Allah will accomplish his purpose. Indeed Allah has set a measure for all things. * " (65: 2-3) And
Translation: " O you who believe! If you obey and fear Allah, He will grant you a criterion (to judge between right and wrong), or a way for you to get out from every difficulty), and will expiate for you your sins, and forgive you. And Allah is the Owner of the Great Bounty. * " (8:29)
Translation: The verses ordering the believers to cling onto and adhere to piety are too many to count. As to the Hadiths:
Translation: 57. Narrated Abu-Huraira ' The people said: " O Allah's Messenger! Who is the most honorable amongst the people (with Allah)? " He said: " The most righteous amongst them. " They said: " We do not ask you about this. " He said: “ Then, Joseph, Allah's Prophet, the son of Allah's Prophet
Translation: , the son of Allah's Khaleel (Abraham)). " They said: " We do not want to ask about this. ": He said: " Then, you want to ask about the descent of the Arabs? Those who were the best in the pre-Islamic period of ignorance will be the best in Islam, provided they comprehend the religious knowledge. " (Bukhari)
Translation: 58. Narrated Abu-Musa: ' We were a group of Al- Asha'ari people who went to the Prophet and asked him to give us something to ride on, but the Prophet ﷺ declined to do so. Then we asked him for a second time to give us something to ride on, but the Prophet ﷺ took an oath that he would not give us anything to ride on. After a while, some camels from the spoils of war were brought to the Prophet and he ordered that five camels be given to us. When we took those camels, we said: " We have made the Prophet forget his oath, so we can never be successful after this. " So I went to the Prophet ﷺ and said: “ O Allah's Messenger! You took an oath that you would not give us anything to ride, but you have given us these. " The Prophet said: " Yes, for if I take an oath and later I see a better solution, then I act on the latter (and give the expiation for the oath). " In another quotation it is said that the Prophet expiated that oath. (Bukhari).
Translation: 59. Narrated Abu-Omama: ' I heard the Messenger of Allah delivering the Khutba in Hajjatol Wada'a (the Farewell Pilgrimage). He said: " Fear Allah your Lord. Perform your five (obligatory) prayers, fast in the month of Ramadhan, pay zakat due on your properties, and obey Allah who is responsible for your affairs, and you will enter His Paradise. " (At-Termizi). The narrator asked Abu-Omama: ' How old were you when you heard this statement? ' He said: ' I was thirty years old. '