In Islam Takfara is to declare someone to be a disbeliever in the religion. Wise Muslims avoid declaring other people who call themselves Muslims disbelievers in the religion where they are able to, because declaring a Muslim to be a Non-Muslim (Pagan/atheist) carries with it many spiritual and social dangers.
The Muslims are those people who have accepted the Message of God and His last Messenger (may God bless him and give him peace) to the planet Earth. They are those who believe in the One True God and associate no partners with Him. They are the ones who recognize the Prophets and Books of God and seek to live a good life in accordance with what is right. They are the people who follow the guidance of the Holy Qur’an and the Sunnah (practices) of the Prophet Muhammad (may God bless him and give him peace).
In one sense the Muslims are the people of the Qibla, which is the direction of the Ka’abah to which God Muslims point as they pray to God. If someone claims to be a Muslim and to hold the essential beliefs of the religion and accept the Laws of God without asserting anything to the contrary then why should people bother him or her? why should they pry into arguments over finer points?
The Muslim Ummah is a brotherhood, a family and a multicultural nation. Muslims should never forget this.