Do the Jahmiyyah differentiate between the actions of the heart and the limbs, and does inward affirmation fall under their category of actions of the heart, such that the absence of awe and fear affects the believer's faith?

The answer is summarized as follows: The Jahmiyyah do not differentiate between the deeds of the hearts and the deeds of the limbs in the definition of faith, for both are excluded from it. Faith, according to them, is merely the knowledge of the heart or its affirmation, and it does not include the deeds of the heart or the limbs. The Jahmiyyah are considered a sect among the Murji’ah, and among their extremists. Jahm bin Safwan went so far as to say that faith is solely the knowledge of Allah, and disbelief is solely ignorance of Him. The Salaf deemed this saying to be disbelief.