(… يا أَيُّهَا الَّذِينَ آمَنُوا آمِنُوا ) (O you who have believed, believe in Allah..): This is the first matter raised by orientalists in many of their books, due to their lack of knowledge of the secrets of the Arabic language, and because orientalists measured the Holy Qur’an on human speech, so that the problem arose. But when we attribute the Qur’an to Allah (swt), we see the matter clearly. There are no limits to Allah’s words:

قُل لَّوْ كَانَ الْبَحْرُ مِدَادًا لِّكَلِمَاتِ رَبِّي لَنَفِدَ الْبَحْرُ قَبْلَ أَن تَنفَدَ كَلِمَاتُ رَبِّي وَلَوْ جِئْنَا بِمِثْلِهِ مَدَدًا

(Say, “If the sea were ink for [writing] the words of my Lord, the sea would be exhausted before the words of my Lord were exhausted, even if We brought the like of it as a supplement.”) (Al-Kahf: 109)

They said: How to ask the believers to believe? It’s like saying to someone who drinks: Drink. This is the human language. As for this speech, it is the word of Allah (swt). There is another verse that says:

 يَا أَيُّهَا النَّبِيُّ اتَّقِ اللَّهَ

(O Prophet, fear Allah) (Al-Ahzab: 1)

Whereas, the Prophet (saws) is the most fearful persons of Allah (swt) on earth!

Hence, when Allah (swt) says to the believers to believe, this means to keep their faith, because faith is not a matter of words, but rather a doctrine:

 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 bedouins say, “We have believed.” Say, “You have not [yet] believed; but say [instead], ‘We have submitted,’ for faith has not yet entered your hearts. And if you obey Allah and His Messenger, He will not deprive you from your deeds of anything. Indeed, Allah is Forgiving and Merciful.”) (Al-Hujurat: 14)

So that, when Allah (swt) asks the Prophet (saws) to fear Him (swt), this means to adhere to all the elements of faith.

(… آمِنُوا بِاللَّهِ وَرَسُولِهِ وَالْكِتَابِ الَّذِي نَزَّلَ عَلَىٰ رَسُولِهِ وَالْكِتَابِ الَّذِي أَنزَلَ مِن قَبْلُ …) (…believe in Allah and His Messenger and the Book that He sent down upon His Messenger and the Scripture which He sent down before.…): Meaning, you have to believe faithfully in Allah (swt) and in the Holy Quran and in The Bible, the Torah, the Psalms, and the Books of Abraham (PBUH), because we believe in all the Messengers of Allah (swt).

( وَمَن يَكْفُرْ بِاللَّهِ وَمَلَائِكَتِهِ وَكُتُبِهِ وَرُسُلِهِ وَالْيَوْمِ الْآخِرِ فَقَدْ ضَلَّ ضَلَالًا بَعِيدًا … ) (…And whoever disbelieves in Allah, His angels, His books, His messengers, and the Last Day has certainly gone far astray.): Belief in Allah (swt), angels and previous books is belief in the unseen. The book is actually in our hands, but being from Allah (swt) is a metaphysical matter, just as sending the Messengers and assigning them to deliver the messages are hidden matters for us. And the last day is hidden as well. The beginning of faith can never be except with belief in Allah (swt) and its end is belief in the Last Day, because the result of belief in the existence of Allah (swt) is the existence of the day of reckoning, reward, punishment, Paradise and Hellfire. And whoever disbelieves in all of them he will have deviated from the correct guidance and strayed far away from its path.