Allah T'ala says in the Holy Quran:

اللَّهُ لا إِلَهَ إِلا هُوَ الْحَيُّ الْقَيُّومُ لا تَأْخُذُهُ سِنَةٌ وَلا نَوْمٌ لَهُ مَا فِي السَّمَاوَاتِ وَمَا فِي الأرْضِ مَنْ ذَا الَّذِي يَشْفَعُ عِنْدَهُ إِلا بِإِذْنِهِ يَعْلَمُ مَا بَيْنَ أَيْدِيهِمْ وَمَا خَلْفَهُمْ وَلا يُحِيطُونَ بِشَيْءٍ مِنْ عِلْمِهِ إِلا بِمَا شَاءَ وَسِعَ كُرْسِيُّهُ السَّمَاوَاتِ وَالأرْضَ وَلا يَئُودُهُ حِفْظُهُمَا وَهُوَ الْعَلِيُّ الْعَظِيمُ

(2:255) Allah: the Everlasting, the Sustainer of the whole Universe; there is no god but He. He does neither slumber nor sleep. Whatsoever is in the heavens and in the earth is His. Who is there to intercede with Him except by His own permission? He knows what is before the people and also what is hidden from them. And they cannot comprehend anything of His knowledge save whatever He Himself pleases to reveal. His Kingdom spreads over the heavens and the earth and the guarding of these does not weary Him. He alone is the Supreme and the Exalted.

This verse is generally known as the 'Verse of the Throne' and it provides in one piece knowledge of God with no parallel.

There is no god but Allah, the Everlasting, the Sustainer of everything.
Regardless of ignorant people's worship of false gods, the truth is that godhead in its entirety, belongs exclusively to the Eternal Being, Who is indebted to no one for His existence. In fact, He is not only self-existent, but upon Him rests the entire order of the universe. He alone wields all sovereign authority over His dominion. None shares His attributes or His power and might, and no one has the same claims against the creatures as He does. Hence, if anywhere in the heavens or earth someone sets up anything or anybody as an object of worship and service (ilah), either instead of or in addition to the One True God, it amounts to declaring war on reality.

“It is no exaggeration to say that Islam and violence are contradictory to each other. The concept of Islamic violence is so obviously unfounded that prima facie it stands rejected. The fact that violence is not sustainable in the present world is sufficient indication that violence as a principle is quite alien to the scheme of things in Islam. Islam claims to be an eternal religion and, as such, could never afford to uphold any principle, which could not stand up to the test of time. Any attempt to bracket violence with Islam amounts, therefore, to casting doubt upon the very eternity of the Islamic religion. Islamic terrorism is a contradiction in terms, much like ‘pacifist’ terrorism. And the truth of the matter is that, all the teachings of Islam are based directly or indirectly on the principle of peace.”