The Command to adhere to Tawhid
Allah says;
فَأَقِمْ وَجْهَكَ لِلدِّينِ حَنِيفًا فِطْرَةَ اللَّهِ الَّتِي فَطَرَ النَّاسَ عَلَيْهَا
So, set you your face towards the religion as a Hanif. Allah's Fitrah with which He has created mankind. No change let there be in Allah's Khalq, that is the straight religion, but most men know not.
Allah says;
`so set your face and persevere in the religion which Allah has prescribed for you, the worship of Allah Alone, the religion of Ibrahim, to which Allah has guided you and which He has perfected for you with the utmost perfection. In this manner, you will also adhere to the sound Fitrah with which He created His creation.'
Allah created His creation to recognize Him and know His Tawhid, and that there is no God except Him, as we have already seen when discussing the Ayah,
وَأَشْهَدَهُمْ عَلَى أَنفُسِهِمْ أَلَسْتَ بِرَبِّكُمْ قَالُواْ بَلَى
and made them testify as to themselves (saying);"Am I not your Lord?"
They said;"Yes!..." (7;172)
And according to a Hadith, Allah said,
إِنِّي خَلَقْتُ عِبَادِي حُنَفَاءَ فَاجْتَالَتْهُمُ الشَّيَاطِينُ عَنْ دِينِهِم
"I created my servants Hunafa (i.e., monotheists), then the Shayatin misled them from their religion."
We will see in the Hadiths that Allah created His creation with the Fitrah of Islam, then among some of them there emerged corrupt religions such as Judaism, Christianity and Zoroastrianism.
لَاا تَبْدِيلَ لِخَلْقِ اللَّهِ
No change let there be in Allah's Khalq,
Some of them said that this means, `do not change the creation of Allah, for if you do, you will divert the people away from the Fitrah with which He created them.'
So it is instructive; just as His saying;
وَمَن دَخَلَهُ كَانَ ءَامِناً
And whoever enters it, he is safe
This is a good and correct interpretation. Others said that this means, Allah made all of His creation equal, all of them have the same sound Fitrah and are by nature upright; they are all born with this nature and there is no disparity among people in this regard.
Ibn Abbas, Ibrahim An-Nakha`i, Sa`id bin Jubayr, Mujahid, Ikrimah, Qatadah, Ad-Dahhak and Ibn Zayd said that the Ayah;
لَاا تَبْدِيلَ لِخَلْقِ اللَّه
(No change let there be in Allah's Khalq),
means, the religion of Allah.
Al-Bukhari said;
لَاا تَبْدِيلَ لِخَلْقِ اللَّه
(No change let there be in Allah's Khalq),
"It means, the religion of Allah, and the religion, and the Fitrah is Islam."
Then he reported that Abu Hurayrah said,
"The Messenger of Allah said;
مَا مِنْ مَوْلُودٍ يُولَدُ إِلاَّ عَلَى الْفِطْرَةِ فَأَبَوَاهُ يُهَوِّدَانِهِ أَوْ يُنَصِّرَانِهِ أَوْ يُمَجِّسَانِهِ كَمَا تُنْتَجُ الْبَهِيمَةُ بَهِيمَةً جَمْعَاءَ هَلْ تُحِسُّونَ فِيهَا مِنْ جَدْعَاءَ
No child is born except in a state of Fitrah, then his parents make him a Jew or a Christian or a Zoroastrian, just as each animal produces a perfect animal like itself -- do you see any among them that are born mutilated?
then the narrator (Abu Hurayrah) said (recite this Ayah),
..
فَطَرَ النَّاسَ عَلَيْهَا لَا تَبْدِيلَ لِخَلْقِ اللَّهِ ذَلِكَ الدِّينُ الْقَيِّمُ
Allah's Fitrah with which He has created mankind. No change let there be in Allah's Khalq, that is the straight religion."
This was also recorded by Muslim.
ذَلِكَ الدِّينُ الْقَيِّمُ
that is the straight religion,
means, adherence to the Shariah and the sound Fitrah is the true, straight religion.
وَلَكِنَّ أَكْثَرَ النَّاسِ لَا يَعْلَمُونَ
but most men know not.
means, most people do not know this and they deviate far astray from it, as Allah says;
وَمَأ أَكْثَرُ النَّاسِ وَلَوْ حَرَصْتَ بِمُوْمِنِينَ
And most of mankind will not believe even if you desire it eagerly. (12;103)
وَإِن تُطِعْ أَكْثَرَ مَن فِى الاٌّرْضِ يُضِلُّوكَ عَن سَبِيلِ اللَّهِ
And if you obey most of those on the earth, they will mislead you far away from Allah's path. (6;116)