"O Abu Hamzah, what makes the blood and wealth of a Muslim forbidden?" He said: "Whoever bears witness to La ilaha illallah (there is none worthy of worship except Allah) and that Muhammad is the Messenger of Allah , faces our Qiblah, prays as we pray, and eats our slaughtered animals, he is a Muslim, and has the same rights and obligations as the Muslims."
Sunan an-Nasa'i Book 37, Hadith 3