What is the ruling on doubting the Holy Quran, the Prophets, and the Quranic figures, and doubting the ruling on a man marrying four wives, and what must be done towards those who promote these ideas on social media?

Among the gravest sins is to cast doubt among Muslims regarding their beliefs and matters of their religion. Whoever denies anything found in the Quran or casts doubt upon it is a disbeliever. The woman's vote is not accepted in matters where the Islamic ruling has been established. Dr. Abd al-Karim Zaidan mentioned that the punishment for apostasy is based on two principles: the Muslim's breach of commitment to the rulings of Islam, and averting harm from society, because the apostate, by declaring their apostasy, deliberately intends to cast doubt among people, cause disorder, and destabilize the state. What must be done with such individuals is to urge them to repent, prevent them from spreading what undermines faith, and respond to their misconceptions. It is incumbent upon the authorities to prevent them from doing so. Ibn al-Qayyim said: "And among God's rights upon His servant is to refute those who attack His Book, His Messenger, and His religion, and to strive against them with argumentation, clear explanation, the sword, the spear, the heart, and the inner being, and beyond that, there is not a mustard seed of faith."