Shaikh Ibn Uthaimeen
The Shaykh said in Sharh Usoolul-Eemanan (pp.4-7):
 The deen (religion) of Islaam: It is the way of life that Allaah sent the Prophet Muhammad sallallaahu ‘alayhi wa sallam with. By it, Allaah terminated the validity of all other religions, perfected this religion for His worshippers, completed His favour upon them and has chosen only this religion for them – no other religion will be accepted by Him from anyone. Allaah – the Most High – said:”Muhammad is not the father of any man amongst you. Rather he is the Messenger of Allaah and the khaatim (last and final) of the Prophets.” [Soorah al-Ahzaab 33:40].