بسم الله الرحمن الرحيم

Shaykh Uthaymīn was asked:

What are the signs of a responsive heart? And the signs of an unresponsive heart?

Shaykh Uthaymīn:
A sign of a responsive heart, is that it humbles itself to the remembrance of Allāh.

And the sign of an unresponsive heart is that it is not affected by what it hears, from the verses of Allah.

Fatāwa Su’āl ‘ala al-Hātif Vol.2 pg 596-597