The scholars mentioned that the third category of apostasy, apostasy of sayings, is like the sea that has no shoreline--meaning the examples could go on and on, and they cited many examples in their books--again, a warning to people not to speak words similar to them. For example, to curse Allah is blasphemy. He who curses Allah is not a Muslim. It is blasphemy to curse one of the Prophets or one of the Angels, as stated by Qadi ^Iyad To declare a Muslim a kafir without a valid reason causes the person to become a non-Muslim, as was mentioned by Mutawalli and al-Ghazaliyy. At-Tahawiyy said that to attribute to Allah any attribute of the creation--like age or time, body or place, organs or instruments, colors or shapes; or to say Allah has a partner or a child--all are blasphemous sayings. Also, intending to blaspheme in the future contingent upon the happening of a certain incident makes the person a blasphemer immediately.
Let the person take heed of the advice and warnings of the Prophet. Let him be extremely cautious not to let his tongue drive him to a destructive situation. As mentioned by Imam alGhazaliyy, the tongue has such a small size but the crime (sin) it could commit could be so great. Other scholars said the tongue is like a fierce beast which will attack you if you do not tie it up. Brother Muslim, learn well this subject of apostasy in an effort to avoid committing any of it. It is an obligation on every Muslim to protect his faith against whatever invalidates, interrupts and terminates it.
Then, if apostasy occurred from one, it is an obligation on him to immediately return to Islam by leaving out what caused him to apostate and uttering with the Testification of Faith (two shahadas) with the intention of clearing himself of apostasy. Left on him is the obligation to regret having committed apostasy and to intend not to go back to something similar in the future.
Apostasy is not an easy issue, and not one to be taken lightly. Many judgments are incurred on the one who apostates from Islam. Some examples are: the apostate's fasting and Dry Purification (Tayammum) are invalid; it is not permissible to eat the meat he slaughters; his wealth not inherited, nor does he inherit; his marriage contract to a Muslim or non-Muslim is not valid. Moreover, the apostate loses all the reward of all the good deeds done prior to his committing apostasy, though all his sins remain. These sins are not erased for him should he go back to Islam, but rather require a separate repentance. Who among the people can afford to have all his good deeds done and rewards earned erased by apostasy, to stand on the Day of Judgment with only his sins to be weighed?
Brother Muslim. Learn well this subject of apostasy. It is the most abhorrent of sins. Do not be fooled by those who claim contrary to what the scholars of Islam classified as apostasy. Do not be led astray to uttering blasphemous words out of ignorance, anger, or carelessness. Do not believe doing so is not blasphemy if not accompanied by liking or believing the meaning of those uttered blasphemous words. Do not believe those who follow their opinions and contradict the rules of the Religion and say: "Who are you to judge others as blasphemous?" while they, themselves, are ignorant of the rules of the Religion on this vital subject, let alone the rules of the tenets of belief (^Aqidah), ablution (Wudu'), Prayer (Salah), and other.
Acquire the personal obligatory knowledge that leads to success and acceptance of Allah and takes away from the tortures of the Hereafter. Equip yourself with the hadith of the Prophet, sallallahu ^alayhi wa sallam, narrated by Ibn Majah: <<If you learn a verse of the Book of Allah, it is more rewardable for you than praying one hundred (100) raka^s (of the supererogatory prayers); and if you go and learn a Chapter of Knowledge it is more rewardable for you than praying one thousand (1,000) raka^s (of the supererogatory prayers).>>