Allah commands His servants to be dutiful to parents, after urging them to 
adhere to belief in His Tawhid, because a person's parents are the cause of his 
existence. So he must treat them with the utmost kindness and respect, his 
father for spending on him and his mother because of her compassion for him. 
Allah says:
[وَقَضَى رَبُّكَ 
أَلاَّ تَعْبُدُواْ إِلاَّ إِيَّـهُ وَبِالْوَلِدَيْنِ إِحْسَـناً إِمَّا 
يَبْلُغَنَّ عِندَكَ الْكِبَرَ أَحَدُهُمَا أَوْ كِلاَهُمَا فَلاَ تَقُل لَّهُمَآ 
أُفٍّ وَلاَ تَنْهَرْهُمَا وَقُل لَّهُمَا قَوْلاً كَرِيمًا - وَاخْفِضْ لَهُمَا 
جَنَاحَ الذُّلِّ مِنَ الرَّحْمَةِ وَقُل رَّبِّ ارْحَمْهُمَا كَمَا رَبَّيَانِى 
صَغِيرًا ]
(And your Lord has decreed that you worship none but Him. And that you be 
dutiful to your parents. If one of them or both of them attain old age in your 
life, say not to them a word of disrespect, nor shout at them, but address them 
in terms of honor. And lower unto them the wing of submission and humility 
through mercy, and say: "My Lord! Bestow on them Your mercy as they did bring me 
up when I was young.'') (17:23-24) Although Allah orders us to show kindness, 
mercy and respect towards them in return for their previous kindness, He says:
[وَإِن جَـهَدَاكَ 
لِتُشْرِكَ بِى مَا لَيْسَ لَكَ بِهِ عِلْمٌ فَلاَ تُطِعْهُمَآ]
(but if they strive to make associate with Me, which you have no knowledge 
of, then obey them not.) meaning, if they are idolators, and they try to make 
you follow them in their religion, then beware of them, and do not obey them in 
that, for you will be brought back to Me on the Day of Resurrection, and Allah 
will reward you for your kindness towards them and your patience in adhering to 
your religion. It is Allah Who will gather you with the group of the righteous, 
not with the group of your parents, even though you were the closest of people 
to them in the world. For a person will be gathered on the Day of Resurrection 
with those whom he loves, meaning, religious love. Allah says:
[وَالَّذِينَ 
ءَامَنُواْ وَعَمِلُواْ الصَّـلِحَـتِ لَنُدْخِلَنَّهُمْ فِى الصَّـلِحِينَ 
]
(And for those who believe and do righteous good deeds, surely, We shall make 
them enter with the righteous.) In his Tafsir of this Ayah, At-Tirmidhi recorded 
that Sa`d said: "Four Ayat were revealed concerning me -- and he told his story. 
He said: "Umm Sa`d said: `Did Allah not command you to honor your parents By 
Allah, I will not eat or drink anything until I die or you renounce Islam.' When 
they wanted to feed her, they would force her mouth open. Then this Ayah was 
revealed:
[وَوَصَّيْنَا 
الإِنْسَـنَ بِوَالِدَيْهِ حُسْناً وَإِن جَـهَدَاكَ لِتُشْرِكَ بِى مَا لَيْسَ 
لَكَ بِهِ عِلْمٌ فَلاَ تُطِعْهُمَآ]
(And We have enjoined on man to be dutiful to his parents; but if they strive 
to make you associate with Me, of which you have no knowledge, then obey them 
not.)'' This Hadith was also recorded by Imam Ahmad, Muslim, Abu Dawud and 
An-Nasa'i. At-Tirmidhi said, "Hasan Sahih.
[وَمِنَ النَّاسِ مَن 
يِقُولُ ءَامَنَّا بِاللَّهِ فَإِذَآ أُوذِىَ فِى اللَّهِ جَعَلَ فِتْنَةَ النَّاسِ 
كَعَذَابِ اللَّهِ وَلَئِنْ جَآءَ نَصْرٌ مِّن رَّبِّكَ لَيَقُولُنَّ إِنَّا كُنَّا 
مَعَكُمْ أَوَ لَيْسَ اللَّهُ بِأَعْلَمَ بِمَا فِى صُدُورِ الْعَـلَمِينَ - 
وَلَيَعْلَمَنَّ اللَّهُ الَّذِينَ ءَامَنُواْ وَلَيَعْلَمَنَّ الْمُنَـفِقِينَ 
]
(10. Of mankind are some who say: "We believe in Allah.'' But if they are 
made to suffer for Allah, they consider the trial of mankind as Allah's 
punishment; and if victory comes from your Lord, they will say: "Verily, we were 
with you.'' Is not Allah Best Aware of what is in the breasts of the creatures) 
(11. And indeed Allah knows those who believe, and verily, He knows the 
hypocrites.)