Praise be to Allah.
We ask Allah, may He be exalted, to increase your reward and grant you the best reward for your efforts in caring for your children and giving them an Islamic upbringing. From your letter, we sense that you have done what Allah, may He be exalted, enjoined upon you with regard to the trust with which He entrusted you.
The fact that your son has drifted away from obedience to his Lord, may He be exalted, and has chosen for himself the path of deviation, misguidance and atheism, should not make you feel anxious or guilty, or feel that the way in which you brought up your children was the cause of that, as was suggested by this deviant son. Rather you have done well and are in a good state, if Allah wills, and others who did not make the effort you made are the ones who have fallen short with regard to themselves and with regard to their children. So do not pay any attention to the whispers of the Shaytaan and do not let what your son said bar you from continuing in your efforts to give your children a good Islamic upbringing and to remain committed and adhering to Islamic teachings.
You should realise that it is not your fault that your son got into this situation and you will not carry the burden of his sins, for you did not spare any effort in teaching him and guiding him to the path of Islam. One who is like you (and spared no effort) cannot be held responsible if some members of his family drift away from the right path (and will not incur any sin). Rather the one who will incur sin is the one who fell short or was negligent in taking care of his children.
We see what happened to the son and wife of Nooh (peace be upon him), and how they were doomed along with those who were doomed, despite the fact that Nooh (peace be upon him) never spared any effort in calling them and trying to guide them. But they did not respond to him, so Allah punished them and they were among those who drowned. Something similar may be said concerning the wife of Loot (peace be upon him) and the father of Ibraaheem (peace be upon him), and Abu Taalib, the uncle of the Prophet (blessings and peace of Allah be upon him). Each of these Prophets and Messengers did what Allah, may He be exalted, had enjoined him to do and fulfilled the trust in the most perfect manner. They did not fall short with regard to their families, but hearts are in the hand of Allah, may He be exalted; He guides whom He wills and He leaves astray whom He wills, and He leaves no one astray astray except the evildoers. Allah, may He be exalted, says (interpretation of the meaning):
“Not upon you (Muhammad (blessings and peace of Allah be upon him)) is their guidance, but Allah guides whom He wills”
“Verily! You (O Muhammad (blessings and peace of Allah be upon him)) guide not whom you like, but Allah guides whom He wills. And He knows best those who are the guided”
Shaykh ‘Abd ar-Rahmaan as-Sa‘di (may Allah have mercy on him) said:
Here Allah, may He be exalted, is saying: Verily you, O Muhammad – and others more so – cannot guide anyone, even those who are the dearest of people to you. No one has the ability to guide anyone, that is, to make them accept guidance or to create faith in their hearts. Rather that is in the hand of Allah alone, may He be glorified and exalted: He guides whomever He wills, and He knows best who is deserving of guidance, so He guides him, and who is not deserving of that, so he leaves him to go astray.
As for the attribution of guidance to the Messenger in the verse in which Allah, may He be exalted, says (interpretation of the meaning), “And verily, you (O Muhammad (blessings and peace of Allah be upon him)) are indeed guiding (mankind) to the Straight Path (i.e. Allah’s religion of Islamic Monotheism)” [ash-Shoora 42:52], that is guidance in the sense of explaining and teaching. The Messenger shows the straight path and encourages people to follow it, doing his utmost to see people follow the path. But as for creating faith in people’s hearts and enabling them to act upon it, he has no ability to do that at all.
Tafseer as-Sa‘di (620).
See also the answer to question no. 12053.
Based on that, you have no option but to pray that he be guided. So turn to your Lord, may He be exalted, and offer a great deal of supplication (du‘aa’) to Him before dawn and when prostrating, in the hope that Allah, may He be exalted, may answer your prayers.
It was narrated that Abu Hurayrah said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “There are three prayers that will undoubtedly be answered: the prayer of one who has been wronged; the prayer of the traveller; and the prayer of a father concerning his child.”
Narrated by at-Tirmidhi (1905), Abu Dawood (1563), and Ibn Maajah (3862); classed as saheeh by al-Albaani in Saheeh at-Tirmidhi.
Al-Azeemabaadi (may Allah have mercy on him) said:
“the prayer of a father” – i.e., for or against his child. The mother is not mentioned because her right is greater, so her prayer is more likely to be answered.
‘Awn al-Ma‘bood, 4/276.
An-Minnaawi (may Allah have mercy on him) said:
“the prayer of a father for his child” – because he sincerely loves him and gives him precedence over himself. Because he is so sincere towards his child, his supplication is more likely to be answered. The mother is not mentioned, despite the fact that she has more right and is closer to her son, which means that her supplication is more likely to be answered than that of the father, because that is self-evident.
Fayd al-Qadeer, 3/301.
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) said:
“the prayer of a father” – in some versions of the hadith it says “against his child” and in some version it is not mentioned; in other words, the father’s prayer may be for or against his child. This is the more correct version; the father’s prayer for or against his child will be answered. As for his praying for him, he prays for him out of compassion and mercy, and whoever shows mercy to people, Allah, may He be glorified and exalted, will show mercy to him. As for praying against him, he cannot pray against his son unless the son deserves that, and if he prays against him when he deserves it, then Allah will answer his prayer.
These are the three answered prayers: the prayer of one who has been wronged; the prayer of the traveller, and the prayer of the parent, whether that is the mother or the father.
Sharh Riyadh as-Saaliheen (3/157), Dar Ibn Haytham edition.
We have explained the conditions of supplication so that it might be acceptable to Allah and be answered, in the answer to question no. 13506.
We have explained the places and times when supplications are answered in the answer to question no. 22438.
With regard to your not helping him to get married, and not going with him to anyone, this is what you should do, even if he stays like that (i.e., single) until the end of his life. That is because people, as you say, will be deceived by what they know of your religious commitment, and will think that your son is like you – or at least, if he is different or has drifted away, no one would ever imagine that he has sunk to that level (i.e., atheism). You should carry on advising him and seek the help of someone who is specialised in such matters who could sit with him, debate with him and answer his doubts. This may be more effective and beneficial than debating on websites.
We ask Allah to guide us and you to the straight path, and to set straight for us the affairs of our spouses and children.
And Allah knows best.