Praise be to Allah.
This problem that this atheist presented to you is not a problem in reality. The scholars have responded to it.
This problem is not limited to the scenario that he mentioned. Rather there are many other similar scenarios. The scholars call this type of issue ‘awl. What it means according to the scholars of inheritance is a case where the sum of the prescribed shares is greater than the inheritance.
The way to resolve this kind of issue is to reduce the share of each of the heirs proportionately in each case of ‘awl. This is what is fair, so that no one heir will bear the entire shortfall whilst others lose nothing [that is, they will all be affected equally].
No case of ‘awl occurred at the time of the Prophet (blessings and peace of Allah be upon him) or of Abu Bakr (may Allah be pleased with him). Rather the issue first arose at the time of ‘Umar ibn al-Khattaab (may Allah be pleased with him), and he was the first one to issue a ruling concerning it, when the case was referred to him of a husband and two sisters (either full sisters or sisters through the father). ‘Umar said: Allah has allocated half to the husband and two thirds to the sisters. If I start with the husband, the two sisters will not be able to have their full share, and if I start with the two sisters, the husband will not be able to have his full share. He consulted the Sahaabah concerning that and they suggested the process of ‘awl, comparing it to the case of debts if they are greater than the estate, in which case the estate is to be divided proportionately so that the shortfall is borne by all the creditors.
The Muslims adopted that from the time of ‘Umar (may Allah be pleased with him) onwards, then ‘Abdullah ibn ‘Abbaas came up with a different view concerning the issue, as he did not favour the view of ‘awl. … Then this difference of opinion ceased to exist, and all the scholars adopted the view of ‘Umar and the majority of the Sahaabah.
Ibn Qudaamah (may Allah have mercy on him) said in al-Mughni:
Today we do not know of anyone who favours the view of Ibn ‘Abbaas (may Allah be pleased with him), and we do not know of any difference of opinion among the contemporary fuqaha’ concerning the issue of ‘awl, praise be to Allah. End quote.
See: at-Tahqeeqaat al-Mardiyyah fi’l-Mabaahith al-Fardiyyah by Shaykh Saalih ibn Fawzaan al-Fawzaan (may Allah preserve him), p. 161-166
Based on that, the solution to the problem mentioned by that atheist is as follows:
The wife gets one eighth, the daughters get two thirds, the father gets one sixth, and the mother gets one sixth.
In order to distribute the estate to the heirs, the estate is to be divided into twenty-four equal parts, which is what the scholars call the “basic figure”, which is the lowest number that will allow the shares of inheritance to be represented by whole numbers. This is similar to the issue of finding the lowest common denominator when adding fractions that have different denominators such as one half and one third.
If we work out the share of each heir in this case, then the share of the wife, which is one eighth, becomes 3/24; the father and mother each get one sixth, which becomes 4/24; and the daughters get two thirds, which becomes 16/24. The total of these shares is 27/24, which is greater than the basic figure, namely 24. This is the issue of ‘awl, which is what that atheist is objecting to.
It is not possible to give each of the heirs his or her share in full, because the estate is not sufficient. In that case, justice dictates that the share of each heir should be reduced commensurate with the shortfall in this scenario. So instead of dividing the estate into twenty-four equal shares, it is divided into twenty-seven equal shares, which is the sum of the shares of all heirs.
So the final division will be as follows:
The wife gets three out of twenty-seven shares, instead of twenty-four, so the one eighth to which she is entitled becomes one ninth, because of the ‘awl process.
Each of the parents gets four shares out of twenty-seven, instead of twenty-four.
The daughters get sixteen shares out of twenty-seven, instead of twenty-four.
So we find that the shortfall affects the shares of all of the heirs, and thus justice is served and the problem mentioned by this atheist is solved.
We would like to take this opportunity to call this person to check himself and reflect upon the path that he is following, and compare it to Islam. He will never find anything more just and better than Islam, for it is the religion of Allah that is preserved from distortion and alteration. Let him look again at the laws of Islam, including this type of inheritance issue, namely ‘awl. He will never find in any other religion that claims to have been divinely revealed, or in any man-made laws, anything more just or better than that.
Let him hasten to enter this religion, so that he will be among those who are saved from the punishment and wrath of Allah, and so that he may attain victory after which there will be no loss.
We ask Allah to guide him.
And Allah knows best.