O people, your Allah is the true Allah, the One, unique in His essence and attributes. There is no other true god, and He is the Merciful and His mercy is vast. He is Compassionate with His creation, surrounding them with many blessings.
And your Ilah (God) is One Ilah (God ـ Allah), La ilaha illa Huwa (there is none who has the right to be worshipped but He), the Most Gracious, the Most Merciful (163)
In this Ayah, Allah mentions that He is the only deity, and that He has no partners or equals. He is Allah, the One and Only, the Sustainer, and there is no deity worthy of worship except Him. He is the Most Gracious ـ Ar-Rahman, the Most Merciful ـ Ar-Rahim. We explained the meanings of these two Names in the beginning of Surat Al-Fatihah. Shahr bin Hawshab reported that Asma' bint Yazid bin As-Sakan narrated that Allah's Messenger ﷺ said:
اسْمُ اللهِ الْأَعْظَمُ فِي هَاتَيْنِ الآيَتَيْنِ
(Allah's Greatest Name is contained in these two Ayat):
وَإِلَٰهُكُمْ إِلَٰهٌ وَاحِدٌ لَّا إِلَٰهَ إِلَّا هُوَ الرَّحْمَٰنُ الرَّحِيمُ
(And your Ilah (God) is One Ilah (God ـ Allah), La ilaha illa Huwa (there is none who has the right to be worshipped but He), the Most Gracious, the Most Merciful.) and:
الم - اللَّهُ لَا إِلَٰهَ إِلَّا هُوَ الْحَيُّ الْقَيُّومُ
(Alif-Lam-Mim. Allah! La ilaha illa Huwa (none has the right to be worshipped but He), Al-Haiyul-Qaiyum (the Ever Living, the One Who sustains and protects all that exists).)(3:1, 2)"
Then Allah mentions some of the proof that He is alone as the deity, that He is the One who created the heavens and the earth and all of the various creatures between them, all of which testify to His Oneness. Allah said:
When the mushrikin مشرکین ، (the associators) of Arabia heard the verse وَإِلَـٰهُكُمْ إِلَـٰهٌ وَاحِدٌ 'And your god is one God', all against their own belief, they were puzzled thinking how could there be just one single object of worship for the whole wide world. If this was a serious claim, there has to be some proof in support. That proof has been tersely encased in the present two verses.
Understanding Tauhid, the Oneness of Allah, in the wider sense:
Tauhid توحید ، the cardinal principle of Muslim faith as stated in Verse 163 has been proved repeatedly and variously, therefore, we limit ourselves at this point to a summary view of the principle as follows:
1. He is One in the state of His being, that is, there exists in the universe of His creation no entity like Him. He is without any duplicate or replica and without any equal or parallel. Such unshared and pristine is His station that He alone is deserving of being called the Wahid واحد ، the One.
2. He is One in claiming the right of being worshipped, that is, in view of the nature of His Being, the comprehensiveness of His most perfect attributes and the great charisma of His creation and its nurture, all human obedience, all ` ibadah عبادہ ، all worship has to be for Him alone.
3. He is One in being free of any conceivable composition, that is, He is free of segments and fragments, units and organs, substances and elements, atoms and particles. There is just no way He can be analyzed or divided or resolved.
4. He is One in being the anterior and the posterior, that is, He existed when nothing did and He will remain existing when nothing will. Who then, if not Him, shall be called the Wahid, the only One? (Jassas)
Mankind has only one God: He is the only worthy focus of man’s attention. Our very existence on earth, and all the benefits we derive from the world around us, are manifestations of His unbounded grace and mercy. In return, we should become God’s devoted servants, living for Him, dying for Him, and setting all our hopes on winning His eternal favour. Man owes everything to his Creator. If he becomes conscious of this, his Lord will mean everything to him, as a mother means everything to her infant.