You non-Muslims are so funny sometimes. No other religion gives the rights to parents as much as Islam does. No other religion emphasizes the responsibilities we have of taking care of parents as much as Islam.
Your Lord has decreed that you worship none but Him, and that you be kind to parents. Whether one or both of them attain old age in thy life, say not to them a word of contempt, nor repel them, but address them in terms of honor." - Al Isra (17:23).
The Prophet, has said that "a person is indeed disgraced, who does not earn Paradise by caring for his parents during the life time and old age of his/her parents".
On another occasion, when asked about the major sins, the holy Prophet replied, "To associate someone with Almighty God, to disobey parents, to kill unlawfully, and to give false evidence".
A person once asked the holy Prophet, "Who has the greatest claim on me with regard to service and kind treatment?" The Holy Prophet replied, "Your mother and again your mother and once again your mother. After her is the claim of your father, then that of your near relatives, and then of the relations next to them". This shows that the claim of a mother is greater than a father over the care that you endow upon them in their old age. Serving and obeying parents is a matter of give and take. Those who treat and obey their parents can rest assured that their children will also show kindness and compassion to them. Respecting and caring the parents is a virtue of the highest order that continues to transcend generation after generation.
Allah says in the Qur'an that if our parents force us to worship anything else besides Allah, then we are not to obey them but "bear them company in this life with justice (and consideration)"
[31: 15]
It is unanimaous amongst the scholars that if Parents tell us to disobey God and the Messenger we don't have to do what they say.
Obeying to parents is linked with worshiping Allah. Shows the importance of obeying parents.
And your Lord decreed that you should worship none but Him and that you be dutiful to your Parents.(quran)
Even when they passed away parents still have rights over you
Malik ibn Rabi’ah Al-Saa’idi narrated: We were sitting with the Messenger of Allah - Sal Allahu alayhi wa Sallam - when an Ansari man came and asked, “O Messenger of Allah, is there anything left from my Birr to my parents that I should present to them after their death?” The Prophet - Sal Allahu alayhi wa Sallam - said, “Yes, four things: Pray and ask forgiveness for them. Fulfill their pledges. Be kind to their friends. And maintain the ties of kinship that come from only their direction. That is what is left from your Birr to them after their death.” [Ahmad, Abu Dawood, and Ibn Maajah]
If the parent is non-Muslim and commits biggest sin, associating partners with God we are still required to be kind and dutiful to them. As long as they don't force us to commit the same sins. We are encouraged to guide them and say words of kindness and pray for them. That is the mercy of our religion and love that people preach but few practice. If you don't like it go find another religion as merciful and just as Islam.
