Is Jahm bin Safwan a disbeliever, despite the possibility of his good intention in searching for his Lord?

Shaykh al-Islam Ibn Taymiyyah mentioned that Jahm ibn Safwan was killed for heresy and atheism, clarifying that among those executed by the sword of justice for heresy, none are known to have been unjustly killed or to have been allies of Allah. He mentioned other examples of those killed for heresy, such as Ja'd ibn Dirham, Ghaylan al-Qadari, Muhammad ibn Sa'id al-Maslub, Bashshar ibn Burd, and al-Suhrawardi, emphasizing that none of the people of knowledge and religion said that they were unjustly killed.