Only the Fools deviate from Ibrahim's Religion
Allah says;
وَمَن يَرْغَبُ عَن مِّلَّةِ إِبْرَاهِيمَ إِلاَّ مَن سَفِهَ نَفْسَهُ وَلَقَدِ اصْطَفَيْنَاهُ فِي الدُّنْيَا وَإِنَّهُ فِي الاخِرَةِ لَمِنَ الصَّالِحِينَ
And who turns away from the religion of Ibrahim (i.e. Islamic Monotheism) except him who fools himself! Truly, We chose him in this world and verily, in the Hereafter he will be among the righteous.
Allah refuted the disbelievers' innovations of associating others with Allah in defiance of the religion of Ibrahim, the leader of the upright. Ibrahim always singled out Allah in worship, with sincerity, and he did not call upon others besides Allah. He did not commit Shirk, even for an instant. He disowned every other deity that was being worshipped instead of Allah and defied all his people in this regard. Prophet Ibrahim said,
فَلَماَّ رَأَى الشَّمْسَ بَازِغَةً قَالَ هَـذَا رَبِّى هَـذَا أَكْبَرُ فَلَمَّأ أَفَلَتْ قَالَ يقَوْمِ إِنِّى بَرِىءٌ مِّمَّا تُشْرِكُونَ
إِنِّى وَجَّهْتُ وَجْهِىَ لِلَّذِى فَطَرَ السَّمَـوَتِ وَالاٌّرْضَ حَنِيفاً وَمَأ أَنَاْ مِنَ الْمُشْرِكِينَ
O my people! I am indeed free from all that you join as partners (in worship with Allah). Verily, I have turned my face towards Him Who has created the heavens and the earth Hanifa (Islamic Monotheism), and I am not of Al-Mushrikin. (6;78-79)
Also, Allah said,
وَإِذْ قَالَ إِبْرَهِيمُ لاًّبِيهِ وَقَوْمِهِ إِنَّنِى بَرَاءٌ مِّمَّا تَعْبُدُونَ
إِلاَّ الَّذِى فَطَرَنِى فَإِنَّهُ سَيَهْدِينِ
(And (remember) when Ibrahim said to his father and his people;"Verily, I am innocent of what you worship. "Except Him (i.e. I worship none but Allah alone) Who did create me; and verily, He will guide me." (43;26-27)
وَمَا كَانَ اسْتِغْفَارُ إِبْرَهِيمَ لاًّبِيهِ إِلاَّ عَن مَّوْعِدَةٍ وَعَدَهَأ إِيَّاهُ فَلَمَّا تَبَيَّنَ لَهُ أَنَّهُ عَدُوٌّ لِلَّهِ تَبَرَّأَ مِنْهُ إِنَّ إِبْرَهِيمَ لَاوَّاهٌ حَلِيمٌ
And Ibrahim's invoking (of Allah) for his father's forgiveness was only because of a promise he (Ibrahim) had made to him (his father). But when it became clear to him (Ibrahim) that he (his father) was an enemy of Allah, he dissociated himself from him. Verily, Ibrahim was Awwah (one who invokes Allah with humility, glorifies Him and remembers Him much) and was forbearing. (9;114)
and,
إِنَّ إِبْرَهِيمَ كَانَ أُمَّةً قَـنِتًا لِلَّهِ حَنِيفًا وَلَمْ يَكُ مِنَ الْمُشْرِكِينَ
شَاكِراً لانْعُمِهِ اجْتَبَـهُ وَهَدَاهُ إِلَى صِرَطٍ مُّسْتَقِيمٍ
وَءاتَيْنَـهُ فِى الْدُّنْيَا حَسَنَةً وَإِنَّهُ فِى الاٌّخِرَةِ لَمِنَ الصَّـلِحِينَ
Verily, Ibrahim was an Ummah (a leader having all the good qualities, or a nation), obedient to Allah, Hanif (i.e. to worship none but Allah), and he was not one of those who were Al-Mushrikin. (He was) thankful for His (Allah's) favors. He (Allah) chose him (as an intimate friend) and guided him to a straight path. And We gave him good in this world, and in the Hereafter he shall be of the righteous. (16;120-122)
This is why Allah said here,
وَمَن يَرْغَبُ عَن مِّلَّةِ إِبْرَاهِيمَ
(And who turns away from the religion of Ibrahim),
meaning, abandons his path, way and method
إِلاَّ مَن سَفِهَ نَفْسَهُ
(except him who fools himself),
meaning, who commits injustice against himself by deviating from the truth, to wickedness.
Such a person will be defying the path of he who was chosen in this life to be a true Imam, from the time he was young, until Allah chose him to be His Khalil, and who shall be among the successful in the Last Life. Is there anything more insane than deviating from this path and following the path of misguidance and deviation instead. Is there more injustice than this!
Allah said,
إِنَّ الشِّرْكَ لَظُلْمٌ عَظِيمٌ
Verily, joining others in worship with Allah is a great Zulm (wrong) indeed. (31;13)
Abu Al-Aliyah and Qatadah said,
"This Ayah (2;130) was revealed about the Jews who invented a practice that did not come from Allah and that defied the religion of Ibrahim."
Allah's statement,
مَا كَانَ إِبْرَهِيمُ يَهُودِيًّا وَلَا نَصْرَانِيًّا وَلَكِن كَانَ حَنِيفًا مُّسْلِمًا وَمَا كَانَ مِنَ الْمُشْرِكِينَ
إِنَّ أَوْلَى النَّاسِ بِإِبْرَهِيمَ لَلَّذِينَ اتَّبَعُوهُ وَهَـذَا النَّبِىُّ وَالَّذِينَ ءَامَنُواْ وَاللَّهُ وَلِىُّ الْمُوْمِنِينَ
Ibrahim was neither a Jew nor a Christian, but he was a true Muslim Hanifa (to worship none but Allah alone) and he was not of Al-Mushrikin. Verily, among mankind who have the best claim to Ibrahim are those who followed him, and this Prophet (Muhammad) and those who have believed (Muslims). And Allah is the Wali (Protector and Helper) of the believers. (3;67-68),
testifies to this fact.
Allah said next,
إِذْ قَالَ لَهُ رَبُّهُ أَسْلِمْ قَالَ أَسْلَمْتُ لِرَبِّ الْعَالَمِينَ