In order to be a Muslim (i.e., to submit oneself to God), it is necessary to believe in the Oneness of God, in the sense of His being the only Creator, Preserver, Nourisher, etc. But this belief, later on called Tawhid Al-Rububiyyah, is not enough. Many of the idolaters knew and believed that only the Supreme God could do all this. To acquire Tawhid Ar-Rububiyyah one must add Tawhid Al-Uluhiyyah, i.e. one acknowledges the fact that it is God alone who deserves to be worshipped, and thus abstains from worshipping any other thing or being.

Having achieved this knowledge of the One True God, man should constantly have faith in Him, and should allow nothing to induce him to deny the truth. When true faith enters a person’s heart, it impacts the person’s outlook and behavior. The Prophet said, “Faith is that which resides firmly in the heart and which is proved by deeds”.

One of the striking results of faith is the feeling of gratitude towards God, which could be said to be the essence of Ibada (worship). The feeling of gratitude is so important that anyone denying the Truth is called kafir, ‘one who is ungrateful.’

A believer loves, and is grateful to God for the bounties He bestowed upon him. He is aware of the fact that his good deeds are far from being commensurate with Divine favors, and therefore he is always anxious to please God. He remembers God often.

The Qur’an promotes this feeling of gratitude by repeating the attributes of God very frequently. “Allah is He, than Whom there is no other god; Who knows (all things) both secret and open; He, Most Gracious, Most Merciful. Allah is He, than Whom there is no other god; the Sovereign, the Holy One, the Source of Peace (and Perfection), the Guardian of Faith, the Preserver of Safety, the Exalted in Might, the Irresistible, the justly Proud glory to Allah! (High is He) above the partners they attribute to Him. He is Allah, the Creator, the Originator, and the Fashioner. To Him belong the Most Beautiful Names: whatever is in the heavens and on earth, doth declare His Praises and Glory: and He is the Exalted in Might, the Wise.” (Al- Qur’an, chapter 59: verse 22-24)

 “Allah! There is no god but He, the Living, the Self-subsisting, Eternal. No slumber can seize Him nor sleep. His are all things in the heavens and on earth. Who is there can intercede in His presence except as He permitteth? He knoweth what (appeareth to His creatures as) before or after or behind them. Nor shall they compass aught of His knowledge except as He willeth. His Throne doth extend over the heavens and the earth, and He feeleth no fatigue in guarding and preserving them for He is the Most High, the Supreme (in glory).” (Al-Qur’an, chapter 2:, verse 255)

 “O People of the Book! Commit no excesses in your religion: Nor say of Allah aught but the truth. Christ Jesus the son of Mary was (no more than) a messenger of Allah, and His Word, which He bestowed on Mary, and a spirit proceeding from Him: so believe in Allah and His messengers. Say not “Trinity”: desist: it will be better for you: for Allah is one Allah: Glory be to Him: (far exalted is He) above having a son. To Him belong all things in the heavens and on earth. And enough is Allah as a Disposer of affairs.” (Al-Qur’an, chapter 4: verse 171)