Qur’an:

“Your Lord has decreed that you should serve Him only, and that your parents should be treated well. If one of them, or both of them, reaches old age with you, do not say to them: “Fie! And do not approach them, but speak kind words to them. And out of mercy lower for them the wing of humility and say: “My Lord, have mercy on them as they raised me when I was little. Your Lord knows better what is inside you. If you are righteous, He is full of forgiveness for those who return again and again.” [Al-Isra’ 17:23-25]

وقضى ربك ألا تعبدوا إلا إياه وبالوالدين إحسانا إما يبلغن عندك الكبر أحدهما أو كلاهما فلا تقل لهما أف ولا تنهرهما وقل لهما قولا كريما واخفض لهما جناح الذل من الرحمة وقل رب ارحمهما كما ربياني صغيرا ربكم أعلم بما في نفوسكم إن تكونوا صالحين فإنه كان للأوابين غفورا

Sunnah:

Jabir reported that a man said to Imam As-Sadiq (a.):“I have parents who are among the opponents (mukhalifin).” He said: “Treat them both as kindly as you kindly treat the Muslims who are near (Wilayah) to us.” [Wasa’il-ush-Shi’ah of Al-Amili, Volume 21 Page 490 Hadith 2]

وعنه، عن أحمد، عن علي بن الحكم، عن سيف بن عميرة، عن أبي الصباح، عن جابر قال: سمعت رجلا يقول لأبي عبد الله عليه السلام: إن لي أبوين مخالفين، فقال: برهما كما تبر المسلمين ممن يتولانا

Ali Ar-Rida (a.) reported that Imam Ali (a.) said: “Treating parents kindly is a duty, even if both are idolaters. However, there is no obedience to them in disobedience to God, nor to others besides them, for one should not obey any creature in disobedience to the Creator.” [Uyun-ul-Akhbar of As-Saduq, Volume 1, page 132]

Mu’awiyah Ibn Wahb reported that Zakariyya Ibn Ibrahim said: “I was a Nazarene and became a Muslim. Then I made a pilgrimage and came in to Ja’far As-Sadiq (a.) and spoke: I was a Nazarene and became a Muslim. He said: “With what did you find Islam?” I said: “The verse: You did not know before of the Book and the Faith, and yet We have made it a light with which We guide whom of Our servants We will.”(42:52) He said: “God, guided you rightly. And he said three times: God, guide him in the right way. Ask what you want, O my son!” I said: My parents and the people of my house are Nazarenes and my mother is blind. May I be with them and eat in their dishes? And he said: “Do they eat pork?” I said: “No, they do not touch it”: He said: “Then there is no problem. Look after your mother and treat her kindly. If she dies, do not leave her to anyone else and be the one to take care of her business. Do not tell anyone that you visited me until you meet me in Mina, God willing.” Then I met him in Mina, with people standing around him as if he were the teacher of children. This one asked him a question and that one asked him a question.When I came to Kufa, I was kind to my mother. I used to feed her, wash her clothes and head and serve her. So she said to me: “O my son, when you belonged to my religion, you did not treat me this way. What is this behavior that I find in you since you emigrated and were purified (Hanif)?” And I said: “A man of the descendants of our prophet has given me these commandments.” She said: “Is this man a prophet?” I said: No, but he is the son of a prophet.” She said: “O my son! this is a prophet, these are the commandments of the prophets.”I said: O my mother! after our prophet no one is a prophet, but he is his son. She said: “O my son! you are the best of believers, reveal it to me.” Then I revealed him to her and she became a Muslim. I gave her my knowledge and she prayed for noon, afternoon, evening and last in the night. Then something showed up with her in the night and she said: “O my son, repeat to me what you have taught me of your knowledge. So I repeated it for her as she confessed and died. When I woke up the next day, the Muslims were the ones who did their washing (Ghusl) and I was the one who prayed for her and descended into her grave.”[Al-Kafi von Al-Kulaini, Band 2 Seite 160 – 161 Hadith 11]

عدة من أصحابنا، عن أحمد بن محمد بن خالد، عن علي بن الحكم، عن معاوية ابن وهب، عن زكريا بن إبراهيم قال: كنت نصرانيا فأسلمت وحججت فدخلت. على أبي عبد الله عليه السلام فقلت: إني كنت على النصرانية وإني أسلمت، فقال: وأي شئ رأيت في الاسلام؟ قلت: قول الله عز وجل: ما كنت تدري ما الكتاب ولا الايمان ولكن جعلناه نورا نهدى به من نشاء فقال: لقد هداك الله، ثم قال: اللهم اهده ثلاثا سل عما شئت يا بني فقلت: إن أبي وأمي على النصرانية وأهل بيتي، وأمي مكفوفة البصر فأكون معهم وآكل في آنيتهم؟ فقال يأكلون لحم الخنزير؟ فقلت: لا ولا يمسونه، فقال: لا بأس فانظر أمك فبرها، فإذا ماتت فلا تكلها إلى غيرك، كن أنت الذي تقوم بشأنها ولا تخبرن أحدا أنك أتيتني حتى تأتيني بمنى إن شاء الله قال: فأتيته بمنى والناس حوله كأنه معلم صبيان هذا يسأله وهذا يسأله، فلما قدمت الكوفة ألطفت لأمي وكنت أطعمها وأفلي ثوبها ورأسها و أخدمها فقالت لي: يا بني ما كنت تصنع بي هذا وأنت على ديني فما الذي أرى عنك منذ هاجرت فدخلت في الحنيفية؟ فقلت: رجل من ولد نبينا أمرني بهذا، فقالت: هذا الرجل هو نبي؟ فقلت: لا ولكنه ابن نبي، فقالت: يا بني إن هذا نبي إن هذه وصايا الأنبياء، فقلت: يا أمه إنه ليس يكون بعد نبينا نبي ولكنه ابنه فقالت: يا بني دينك خير دين، اعرضه علي فعرضته عليها فدخلت في الاسلام وعلمتها، فصلت الظهر والعصر والمغرب والعشاء الآخرة، ثم عرض لها عارض في الليل، فقالت: يا بني أعد علي ما علمتني فأعدته عليها، فأقرت به وماتت، فلما أصبحت كان المسلمون الذين غسلوها وكنت أنا الذي صليت عليها ونزلت في قبرها

Abu Ja’far reported that Imam Ar-Rida (a.) said: “The one who loves his people, even if they are unbelievers, is not to be blamed.” [Mustatrafat-us-Sara’ir of Abu Abdillah Al-Hilli, page 576]

عن محمد بن إدريس عن أبي جعفر عن أبي الحسن عليه السلام قال لا لوم على من أحب قومه وإن كانوا كفارا