Allah is the one and only God who deserves to be worshipped. This document discusses some of the fundamental teachings of Touheed, or Islamic monotheism, including that Allah is the sole Creator and Sustainer of the universe and that He alone deserves to be worshipped without any partners. It also notes that associating any partners with Allah, whether it be other gods, idols, saints, or other beings, is considered shirk, the only sin that Allah does not forgive if one dies without repenting from it.