He is Allah, the One there is no Deity except Him, the King, the Holy, the Peace, the Believer, the Safeguard, the Exalted, the Tyrant, and the Arrogant; Glory to Allah from whatever they have been associating.
The names Al-Mu’min (The Believer) and Al-Muhaimin (The Safeguard), which are among the best names of Allah, are mentioned only in this verse. The people of Messenger Muhammad, who have inherited the Lord’s Book—as explained in verse 35:32—are obligated to familiarize mankind with Allah in their hearts' language, as Adhikr—the Speech of Allah and the Truth—commands. However, only the one-in-a-thousand true believer among them, who testifies to the 40 names of Adhikr, will fulfill this responsibility, as explained in verse 32:4. The remaining 999 are the Fujjar who recite the Arabic Quran but are destined for one of the seven doors of Hellfire, as described in verse 15:44. They are the Mujrim who serve Satan, as explained in verses 36:59-62. See explanations of 5:48, 36:83, and 39:67.