God's Attributes are His Own Essence
While researching the hadith of Imam al-Reza (A.S.) in this regard, we come across his treatment of the issue of His Attributes which are none other than a description of His Own Essence, and that it is impossible that they should be anything else. For example, al-Husayn ibn Khalid said, "I heard al-Reza (A.S.) saying, "God has always been Knowing, omni-Potent, Living, Eternal, Hearing, Seeing,' so I said to him, `O son of the Messenger of God (S.A.W.)! People have been saying that God knows through His faculty of knowledge, omni-Potent through His faculty of power, Eternal through His ability to withstand time, Hearing through His faculty of hearing, and Seeing through His faculty of vision.' He (A.S.) said, `Anyone who says so and believes in it has indeed accepted other gods besides God, and he has nothing to do with our religion.' Then he added, `God has always been Knowing, omni-Potent, Eternal, Hearing, and Seeing in His Own Essence; Exalted is God above the claims of the polytheists and those who make such similitudes a great deal of exaltation.'"
Knowledge, might, and other attributes of God are not actually different from His Essence; rather, they are the same like the Essence in their existence and reality; otherwise, they would have been partners with God in His eternity which contradicts the very concept of tawhid which agrees with the nature of His being, that is, the eternity of the Self on its own, without having anything else as partner therewith.
Belief in Plurality of the Essence and Attributes is Shirk
In another hadith reported by Muhammad ibn Arafa, Imam Reza (A.S.) explains to us how one will be committing shirk if he considers the Essence of the Almighty and His Attributes as separate from each other. Muhammad said, "I asked al-Reza (A.S.), `Did God create things by some sort of power or not?' He answered, `It is not possible that He must have used some sort of power to do so because if you say that He created things by a power, you would be saying that you imagined a tool whereby He created things, which is shirk. And if you say that He created things which He subjected to His power, you would be saying that He made sure He would be able to overpower them, while He is not weak or incapable or in need of anyone else; rather, He, Glory be to Him, is Almighty due to the fact that His own Essence is Mighty.'"