Ruling on Takfir of a Muslim for committing a sin

Q 1: What is the ruling on Takfir (declaring a Muslim as a disbeliever)? In Egypt, there is a group that declare Muslims as Kafirs (disbelievers) for committing sins other than Shirk (associating others with Allah in His Divinity or worship). Can committing minor or major sins render someone a Kafir despite their declaration of the Shahadah (Testimony of Faith)?

A: Major sins differ with respect to the gravity of the offence; some of them are Shirk and others are not. Ahl-ul-Sunnah wal-Jama`ah (adherents to the Sunnah and the Muslim mainstream) do not declare Muslims to be Kafirs if they commit sins other than Shirk, such as killing, drinking alcohol, Zina (sexual intercourse outside marriage), theft, consuming orphans' property, slandering chaste Muslim women, and consuming Riba (usury), and other major sins. In these cases, the ruler should carry out the penalty prescribed for the sin they commit, such as Qisas (just retaliation), Had (prescribed punishment), or Ta`zir (discretionary punishment). The person should perform Tawbah (repentance to Allah) and seek forgiveness. However, if the major sin is such as seeking the help of other than (Part No. 2; Page No. 137) Allah, for example, making Du`a' (supplications) to the dead to relieve distresses, or making vows to and slaughtering for the dead, these and similar acts are all major sins and acts of Kufr (disbelief). It is obligatory that this should be explained to those who commit them and they should be given the evidences. If they perform Tawbah after the explanation, this will be accepted; otherwise the ruler should execute them for Riddah (apostasy).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.