Q: After establishing the five Pillars mentioned in the Hadith, is there anything other than Shirk (associating others with Allah in His Divinity or worship) that can render someone a Kafir (disbeliever)?

A: Islam means to testify that there is no god but Allah and that Muhammad is the Messenger of Allah, to establish Salah (Prayer), to give Zakah, to perform the Sawm (Fast) of Ramadan, and to perform Hajj to the Ka`bah if one is able to do so. Iman (Faith) means to believe in Allah, His Angels, His Books, His Messengers, the Last Day, and predestination, both good and evil. Ihsan (the perfection of Faith) means to worship Allah as if you can see Him; and if you cannot see Him, know He can see you.Islam is related to the apparent acts, while Iman is related to (Part No. 2; Page No. 11) the hidden ones. Islam and Iman are inseparable; Islam is not correct without Iman nor is Iman without Islam.There are many Mukaffirat (deeds or words that can render a person a Kafir [disbeliever]) that are called the nullifiers of Islam. The gravest of which is Shirk, and it includes deeds such as supplicating to the dead and seeking help from them, and supplicating to idols, trees, stars, and the like. This is because when the Prophet (peace be upon him) was asked, "Which is the gravest sin?" He (peace be upon him) replied, "To associate another with Allah, when it was He Who created you." Reported by Al-Bukhary and Muslim. Other examples of Mukaffirat are insulting Allah and His Messenger, and mocking Islam, such as by denying religious matters that are well established to be Wajib (obligatory) like Salah and Zakah, and denying religious matters well established to be Haram (prohibited) like Zina (sexual intercourse outside marriage) and stealing.Shaykh Al-Islam, Muhammad ibn `Abdul-Wahhab (may Allah be merciful to him) identified ten Mukaffirat. They are listed in the compilation: "Al-Tawhid (Monotheism)," (p. 271) and published in a separate booklet. If you want to increase your knowledge on this issue, refer to the chapters on the ruling on apostates in the books on Fiqh (Islamic jurisprudence).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.