According to (Al-Hojorat:14)
قَالَتِ الْأَعْرَابُ آمَنَّا قُل لَّمْ تُؤْمِنُوا وَلَٰكِن قُولُوا
أَسْلَمْنَا وَلَمَّا يَدْخُلِ الْإِيمَانُ فِي قُلُوبِكُمْ وَإِن
تُطِيعُوا اللَّهَ وَرَسُولَهُ لَا يَلِتْكُم مِّنْ أَعْمَالِكُمْ
شَيْئًا إِنَّ اللَّهَ غَفُورٌ رَّحِيمٌ
The desert Arabs say, "We believe." Say, "Ye have no faith; but ye
(only) say, 'We have submitted our wills to Allah,' For not yet has
Faith entered your hearts. But if ye obey Allah and His Messenger, He
will not belittle aught of your deeds: for Allah is Oft-Forgiving,
every person who starts Islam is a Muslim (although Muslim can be any submission to Allah as well, as may be the case for even people of the book). The name of Islam is Islam to show its highest goal (being submitted to Allah) but this submission has only one constraint, it should be truthful not only a word of mouth or even a decision of mind not backing with proper behavior at the times of examinations.
- So becoming Muslim starts from saying the world by mouth (say, after seeing a spark of light in the hearth, an evolution in hearth, feeling a presence of Allah and similarly other cases).
- Then this statement absorbs examinations to the new Muslim, he would be examined at the same time that he is gradually learning Islam, its ideology and Shari'ah. The examinations have at least one important objective, the person would find his weak points as Allah says "For thy Lord is (as a Guardian) on a watch-tower" (Al-Fajr:14), he can either choose to accept the weak point and try to resolve it or simply deny it arrogantly.
- He cannot pass to a higher level until he passes the examinations successfully, step by step.
- At some point (perhaps from the very beginning that he faces the examinations for the first time and decide to overcome his weak points, switching from only tongue to also mind situation?) the rather new Muslim will feel the joy of presence of Allah all over around as a sign of faith, as faith is now touching his hearth.
- However, he is now only a beginner in being faithful as Allah says: "O ye who believe! Believe in Allah and His Messenger, and the scripture which He hath sent to His Messenger and the scripture which He sent to those before (him). Any who denieth Allah, His angels, His Books, His Messengers, and the Day of Judgment, hath gone far, far astray."(An-Nesaa':136) or similarly "O ye that believe! Fear Allah, and believe in His Messenger, and He will bestow on you a double portion of His Mercy: He will provide for you a Light by which ye shall walk (straight in your path), and He will forgive you (your past): for Allah is Oft-Forgiving, Most Merciful."(Al-Hadid:28). The point to focus on here is "O ye who believe! Believe …" so that becoming faithful has degrees, the Muslim should travel his journey toward Allah step by step. There are a bunch of verses guiding the believer how to think and behave for him to improve, as Quran is the book of guidance for those who believe (according to Quran itself)!
- Faith and fear of Allah (fear of his Justice, being decent before his majesty: Taghva) are related to each other as faith in hearth causes Taghva in behavior (avoiding sins and not being in observance to his commands), Taghva in behavior brings back confidence (yagheen) which again makes the faith of the faithful person stronger. This chain is the right way (Serat-e-Mostaghim) toward Allah that no one reaches it but the truthful men, those who say we believe and then prove it in action (Al-Aghaf:13, Fosselat:30):
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.
and the 14 innocents A.S. are the most sincere ones, and the prophet S.A says:
"And I am commanded to be the first (foremost) of those who bow to Allah in
To sum up all the above stated things, Muslim in Quran (when is used for Muslims really and not anyone who submits to Allah, whether or not has stated the words of "Shahaadatein": Allah is unique and Muhammad S.A. is his prophet) include both who have just entered Islam, no faith even touching their hearth, to the foremost of all the Muslims and faithful creatures of Allah the holy prophet Muhammad S.A., and should be easily understandable as anyone who enters a religion/ism would be called with a title taken from the name of that religion/ism, but the name of the religion/ism itself should already have an eye open to the ending point of that religion/ism as well. To speak strictly, anyone who says the "Shahaadaatein" (accepting Allah as the only God through the prophecy of his prophet Muhammad S.A.) will be Muslim, that is, not Kafir. So that even a "yet unbeliever" (different than unbeliever who is not also tended to believe) is not that unbeliever which is known as Kafir (atheist)! Confessing to be Mulsim and not being hypocrite equals being Muslim in view of Allah.
PS. Shirk, opposite of Islam, has also a similar gradual structure, the biggest being stating that God is not unique or there are gods with Allah, to that we believe in uniqueness of Allah but follow our will instead of his will in action, although we know he is the only ruler of the world and has no coadjutor, not my will and not any will other than his, be it the will of my society, its government, my family, the world-wide will, or else.