[Quran – 20:14] “Verily! I am Allah! La ilaha illa Ana (none has the right to be worshipped but I), so worship Me, and perform As-Salat (Iqamat-as-Salat) for My Remembrance”
The Prophet (Peace Be Upon Him) has said: [Muslim, Book#001, Hadith #0047] “It is narrated on the authority of Mu’adh b. Jabal that he observed: I was riding behind the Messenger of Allah (may peace be upon him) on an ass known as ‘Ufair. He (Mu’adh) observed: He (the Holy Prophet) said: Mu’adh, do you know what right has Allah over His bondsmen and what right have His bondsmen over Him? Mu’adh added: I replied: Allah and his Messenger know best. Upon this, the Holy Prophet remarked: The right of Allah over His bondsmen is that they should worship Allah and should not associate anything with Him, and the right of His bondsmen over Allah, Glorious and Sublime, is that He does not punish him who associates not anything with Him. He (Mu’adh) added: I said to the Messenger of Allah: Should I then give the tidings to the people? He (the Holy Prophet) said: Do not tell them this good news, for they would trust in it alone.”
[Bukhari, Book #72, Hadith #850] “Narrated Mu’adh bin Jabal While I was riding behind the Prophet and between me and him and between me and him there was only the back of the saddle, he said, “O Mu’adh!” I replied, “Labbaik, O Allah’s Apostle, and Sa’daik!” he said, “Do you know what is Allah’s right upon his slave?” I said, “Allah and His Apostle know best” He said, “Allah’s right upon his slaves is that they should worship Him alone and not worship anything else besides Him.” Then he proceeded for a while and then said, “O Muadh bin Jabal!” I replied, “Labbaik, O Allah’s Apostle: Sa’daik!’ He said, “Do you know what is the right of the slaves upon Allah if they do that?” I replied, “Allah and His Apostle know best.” He said, “The right of the slaves upon Allah is that He will not punish them (if they do that).”
[Sunan Abu Dawud, Book #9, Hadith #1577] “Narrated Abdullah ibn Mu’awiyah al-Ghadiri: Abu Dawud said: I read in a document possessed by Abdullah ibn Salim at Hims: Abdullah ibn Mu’awiyah al-Ghadiri reported the Prophet (peace be upon him) as saying: He who performs three things will have the taste of the faith. (They are:) One who worships Allah alone and one believes that there is no god but Allah; and one who pays the zakat on his property agreeably every year. One should not give an aged animal, nor one suffering from itch or ailing, and one most condemned, but one should give animals of medium quality, for Allah did not demand from you the best of your animals, nor did He command you to give the animals of worst quality.”