Q 4: Some people do not practice Islam at all. They do not recite Qur’an or even know one Ayah of it.
They do not offer Salah (prayer) nor pay Zakah (obligatory charity). They even curse the religion and the Messenger of Allah (peace be upon him). What is worse is that they curse Allah, daily, yet still claim to be Muslims who testify that there is no deity except Allah and that Muhammad is His Messenger. Is it permissible to eat the meat of their slaughtered animals,
even though in our society there are so many of such people.
First of all:
Abandonment of Salah and denying its obligation is an act of Kufr (disbelief) according to Ijma‘ (consensus) of scholars. Similarly, the abandonment of Salah due to laziness and carelessness is also an act of Kufr according to the more preponderant of the two opinions held by the scholars. (Part No. 2; Page No. 18)
Cursing Allah and His Messenger as well as cursing the religion is major Kufr (disbelief) and an act of Riddah (apostasy) from Islam. Thus, whoever does this should be urged to repent. If the person refuses to do so, it is obligatory on the ruler to inflict capital punishment; based upon the statement of the Prophet (peace be upon him):
Whoever (a Muslim) changes his religion, execute him.
Al-Bukhari in his Sahih (Book of Authentic Hadith).
It is impermissible to eat from the slaughtered meat of apostates until they repent. If they sincerely repent, the meat of the animals which they slaughter thereafter becomes lawful to eat from. The same also applies to other disbelievers, except for the People of the Book. Even if an apostate testifies that there is no deity except Allah and Muhammad is His Messenger, the Testimony of Faith will be of no benefit to the one who says it while committing that which nullifies Islam according to the Ijma‘ (consensus) of Muslim scholars.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.