There is a Difference between a Believer and a Muslim
Allah chastises the Bedouins who, when they embraced Islam, claimed for themselves the grade of faithful believers. However, Faith had not yet firmly entered their hearts,
قَالَتِ الاْاَعْرَابُ امَنَّا
قُل لَّمْ تُوْمِنُوا وَلَكِن قُولُوا أَسْلَمْنَا وَلَمَّا يَدْخُلِ الاِْيمَانُ فِي قُلُوبِكُمْ
The Bedouins say;"We believe."
Say;"You do not believe, but say, `We have submitted,' for Faith has not yet entered your hearts..."
This honorable Ayah provides proof that Faith is a higher grade than Islam, according to the scholars of the Ahl us-Sunnah wal-Jama`ah. This is also demonstrated in the Hadith of Jibril, peace be upon him, when he questioned the Prophet about Islam, then Iman then Ihsan. Thus moving the general matter to one more specific, then even more specific.
Imam Ahmad recorded that `Amir bin Sa`d bin Abi Waqqas said,
"The Messenger of Allah gave (something to) some men and did not give one of them. Sa`d said, `O Allah's Messenger, you gave to so-and-so and so-and-so. However, you gave nothing to so-and-so, even though he is a believer.'
The Prophet said,
أَوْ مُسْلِمٌ
(Or say, a Muslim),
Sa`d repeated his statement thrice each time the Prophet answered,
أَوْ مُسْلِمٌ
(Or say, a Muslim),
إِنِّي لَاُعْطِي رِجَالاً وَأَدَعُ مَنْ هُوَ أَحَبَّ إِلَيَّ مِنْهُمْ فَلَمْ أُعْطِهِ شَيْيًا مَخَافَةَ أَنْ يُكَبُّوا فِي النَّارِ عَلَى وُجُوهِهِم
I might give some men and give nothing to others, even though the latter are dearer to me than the former. I do not give them things for fear that they might be thrown on their faces in the Fire."
This Hadith is recorded in the Two Sahihs.
Therefore, the Prophet made a distinction between the grade of believer and the grade of Muslim, indicating that Iman is a more exclusive grade than Islam.
I mentioned this subject in detail supported by evidence, in the beginning of the explanation of the chapter on Iman in Sahih Al-Bukhari, all praise is due to Allah and all the favors are from Him.
So this proves that the Bedouins whom the Ayah mentioned were not hypocrites, rather they were Muslims in whose hearts Faith was not yet firmly established. They claimed a higher grade for themselves than the grade that they earned, and they were taught a lesson as a consequence.
This meaning agrees with the meaning given by Ibn Abbas, Ibrahim An-Nakha`i, Qatadah and that preferred by Ibn Jarir. These Bedouins were taught a lesson,
لَّمْ تُوْمِنُوا وَلَكِن قُولُوا أَسْلَمْنَا وَلَمَّا يَدْخُلِ الاِْيمَانُ فِي قُلُوبِكُمْ
Say;"You do not believe, but say `We are Muslims,' for Faith has not yet entered your hearts..."
meaning, `you have not yet achieved the reality of Faith.'
Allah the Exalted said,
وَإِن تُطِيعُوا اللَّهَ وَرَسُولَهُ لَاإ يَلِتْكُم مِّنْ أَعْمَالِكُمْ شَيْيًا
But if you obey Allah and His Messenger, He will not decrease anything in reward for your deeds...
`He will not decrease any of your rewards,' as Allah said;
وَمَأ أَلَتْنَـهُمْ مِّنْ عَمَلِهِم مِّن شَىْءٍ
We shall not decrease the reward of their deeds in anything. (52;21)
Allah said;
إِنَّ اللَّهَ غَفُورٌ رَّحِيمٌ
Verily, Allah is Oft-Forgiving, Most Merciful.
(for those who repent and return to Him).
Allah's statement