Every language has one or more terms that are used in reference to God and sometimes to lesser deities. This is not the case with the word ‘Allah’. Allah is the personal name of the One True God. Nothing else can be called Allah. The term has no plural or gender. This shows its exclusivity when compared to the word ‘god’ which can be made plural, i.e. ‘gods’ or feminine, i.e. ‘goddess’. It is interesting to note that Allah is the personal name of God in Aramaic, the language of Jesus (p). The word Allah is a reflection of the unique concept that Islam associates with God. To a Muslim, Allah is the Almighty, Creator and Sustainer of the universe, who is similar to none and nothing is comparable to Him. The Prophet Muhammad (p) was asked by his contemporaries about Allah. The answer came directly from God Himself in the form of a short chapter of the Qur’an that is considered the essence of the Unity of God or the motto of monotheism. “Say: He is Allah, the One; Allah, the Eternal, Absolute; He begetteth not, nor is He begotten, and there is none like unto Him.” [Al-Qur’an 112:1-4]
Some non-Muslims allege that the concept of God in Islam is that of a stern and cruel God who demands to be obeyed fully. He is not loving and kind. Nothing can be farther from the truth than this allegation. It is enough to know that with the exception of one, each of the 114 chapters of the Qur’an begins with the verse: “In the Name of Allah, Most Gracious, Most Merciful” In one of the sayings of Prophet Muhammad (p) we are told: “God is more loving and kinder than a mother to her dear child.”
From: whyislam.org