Q 1: A man has a number of sons and daughters, of them some were guided by Allah, had good character and reputation, feared Allah, obeyed the Messenger, and were kind to their parents while others acted viciously, did not listen to any advice, and were not good to their parents. The question is: Are all those children equal as far as their rights of inheritance are concerned? In other words, is the mannerless child, whether male or female, entitled to receive their prescribed share of their father's inheritance as explained in Allah's saying in Surah Al-Nisa':
There is a share for men and a share for women from what is left by parents and those nearest related
Allâh commands you as regards your children’s (inheritance): to the male, a portion equal to that of two females
I understand that the virtuous son or daughter who obeys their Lord, follows the Sunnah (whatever is reported from the Prophet), and is dutiful to their parents should receive their prescribed share of inheritance but what should be done with children of bad characters and negligence of Din (religion) while Allah (Glorified be He) Whose Words are nothing but the Plain Truth says:
Worship Allâh and join none with Him (in worship); and do good to parents
(Part No. 16; Page No. 556) He (Glorified and Exalted be He) also says:
...give thanks to Me and to your parents. Unto Me is the final destination.
And He (Glorified and Exalted be He) says to Prophet Nuh (Noah, peace be upon him):
And Nûh (Noah) called upon his Lord and said, "O my Lord! Verily, my son is of my family! And certainly, Your Promise is true, and You are the Most Just of the judges."
He said: “O Nûh (Noah)! Surely, he is not of your family; verily, his work is unrighteous"
I have heard contradictory opinions regarding this issue. Some denied the right of disobedient children to inherit from their parents while others ascertained that inheritance is the right of the obedient and disobedient children alike. Thus I find myself in a maze of different views in which I fear getting lost. I therefore refer to you to know the true ruling of Allah and guidance of His Prophet regarding this issue.
When someone dies, it is the Shar`y (Islamic legal) judiciary that defines their heirs and the shares that they are entitled to. If the corruption of any of the heirs reaches the degree of Kufr (disbelief) and leaving the realm of Islam, they are to be deprived of receiving inheritance for the existence of an impediment, which is the Riddah (apostasy), of the concerned person.
However, if the Munkar (that which is unacceptable or disapproved of by Islamic law and Muslims of sound intellect) that such a person committed did not reach the degree of Riddah and leaving the realm of Islam, they are entitled to receive their share of inheritance. The foregoing is supported by the generality of the Ayahs (Qur'anic verses) and Hadiths to that effect. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.