To warn the one who is alive, and the word of punishment may come true upon the disbelievers.
Adhikr is sent down to warn those who are alive so that punishment may come true upon the disbelievers. Those who use it for other purposes, the verses they saw, heard, and read will argue and witness against them, pushing them into Hell. They will witness against their soul that indeed they were disbelievers at the time of their death, as told in verse 7:37, and will enter the house of Satan—the disbeliever.
The disbelievers during the period of Messenger Muhammad didn’t have a codified Book. When the Messenger was explaining Adhikr, they were fleeing from it like wild donkeys fleeing from the lion’s roar, as explained in verses 74:49-51. Today’s Arabic Quran-reading Fujjar are also fleeing from Adhikr. Moreover, instead of warning those who are alive with the verses of Adhikr, they are reciting the verses of the Arabic Quran over the dead, ignoring verse 36:70. See explanation 6:36; 30:52-53; 35:22.