What you have to do is to advise your brother to pray regularly, and tell him of the ruling of Allaah concerning one who does not pray. Do not let him slaughter the meat for you himself, and tell him the reason why, which is that the one who does not pray is regarded as a kaafir, so meat slaughtered by him is not halaal. Perhaps knowing the ruling will have an effect on him, and he will come back to his religion and start to pray regularly. This will be better for him in his religious and worldly affairs, in this world and in the Hereafter.
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him) was asked:
Is it permissible to eat meat slaughtered by one who deliberately does not pray, knowing that if he is told of that he will claim that he says the Shahaadah? What should we do if we cannot find any butcher who does pray?
If a person does not pray, we should not eat meat slaughtered by him. This is the correct view, because the Prophet (peace and blessings of Allaah be upon him) said: “Between a man and shirk and kufr there stands his giving up prayer.” Narrated by Muslim in his Saheeh from Jaabir ibn ‘Abd-Allaah al-Ansaari (may Allaah be pleased with him). And the Prophet (peace and blessings of Allaah be upon him) said: “The covenant that stands between us and them is prayer; whoever does not pray is a kaafir.” Narrated by Imam Ahmad and the four authors of Sunan with a saheeh isnaad from Buraydah ibn al-Husayb (may Allaah be pleased with him). And he said: “The head of the matter is Islam and its pillar is prayer.” Narrated by Imam Ahmad and al-Tirmidhi with a saheeh isnaad from Mu’aadh ibn Jabal (may Allaah be pleased with him). If the pillar of a thing falls, it cannot stand straight or remain; when the pillar falls, whatever rests on it falls too.
Thus it is known that the one who does not pray has no religion, so meat slaughtered by him cannot be eaten. If you are living in a land where there are no Muslim butchers, you should laughter your own meat and use your hands to do something that will be benefit to you, or look for a Muslim butcher to slaughter meat for you even in his own house. Praise be to Allaah, this is something easy so you should not be heedless about this matter.
You should advise this man to fear Allaah and pray. His suggestion that the Shahaadatayn is sufficient is a serious mistake, because the Shahaadatayn come with conditions that must be fulfilled, as the Prophet (peace and blessings of Allaah be upon him) said: “I have been ordered to fight the people until they bear witness that there is no god except Allaah and that I am the Messenger of Allaah, and establish regular prayer and pay zakaah. If they do that, then their blood and wealth are safe from me, except in cases dictated by Islamic law, and their reckoning will be with Allaah.” Saheeh – agreed upon.
So prayer and zakaah are mentioned alongside the Shahaadatayn. According to another version: “I have been commanded to fight the people until they say Laa ilaaha ill-Allaah, and if they say Laa ilaaha ill-Allaah, then their blood and wealth are safe from me, except in cases dictated by Islamic law, and their reckoning will be with Allaah.” Prayer is one of these conditions and zakaah is one of these conditions.
What the believer must do is fear Allaah, and everyone who claims to be a Muslim must fear Allaah and offer the five prayers regularly, for prayer is the foundation of Islam and it is the greatest of the five pillars of Islam after the Shahaadatayn. Whoever neglects it neglects his religious commitment, and whoever does not pray has left the faith. We ask Allaah to keep us safe and sound.
This is the truth and this is what is correct. Some of the scholars said that such a person is not a kaafir in the sense of major kufr, rather his kufr is minor kufr, and he is a sinner who has committed a grave sin, one that is worse than adultery, worse than stealing, worse than drinking alcohol. But he is not a kaafir in the sense of major kufr unless he denies that prayer is obligatory. This is the view of a number of scholars. But the correct view is that which is indicated by the words of the Prophet (peace and blessings of Allaah be upon him), which is that such a person is a kaafir in the sense of major kufr, as stated in the ahaadeeth quoted above, because he has neglected the pillar or foundation of Islam which is prayer.
We should not take this matter lightly. ‘Abd-Allaah ibn Shaqeeq al-‘Aqeeli, the great Taabi’i (may Allaah have mercy on him) said: “The companions of the Prophet (peace and blessings of Allaah be upon him) did not regard the omission of anything as being kufr, except in the case of prayer.”
And he mentioned that the Sahaabah were unanimously agreed that the one who did not pray was a kaafir in their view. We ask Allaah to keep us safe and sound.
So we must be careful, and adhere to this important obligation and not take the matter lightly if someone does not pray. We should not eat meat slaughtered by him, or invite him to any feasts, or accept his invitations. Rather he should be shunned until he repents to Allaah and starts to pray. We ask Allaah to guide us all. End quote.
Majmoo’ Fataawa al-Shaykh Ibn Baaz, 10/274-276
See also the answer to question no. 1553
And Allaah knows best.