Members of Ibn Sīnā’s household were followers of these Qarmatians, among those who had responded to the call of al-Hākim, who was in Egypt. Ibn Sīnā said:

“It was for this reason that I took up philosophy.”

Likewise, the authors of the Epistles of the Brethren of Purity agreed with them. These epistles were composed according to their approach during the fourth century AH, when Cairo was built. The affairs of the Muslims were in great turmoil during that period.

[Ibn Sīnā’s Statements in the Adhawiyya Treatise]

The point here is that these atheists argue against those who deny the divine attributes by appealing to their shared denial of the attributes and disregard for what the scriptural verses indicate. Ibn Sīnā mentioned this in the Adhawiyya Treatise, which he composed on resurrection for certain leaders whose favor he sought, so that they would grant him the prestige and wealth he desired from them. He explicitly stated this at the beginning of the treatise.

After mentioning the argument of those who affirmed bodily resurrection, and explaining that what prompted them to do so was the religious law’s teaching concerning the resurrection of the dead, he said:

“As for religious law, one rule must be understood concerning it: namely, that