For those who feel their hearts are unaware, make dhikr of Allah.

We created many of the jinn and the mankind for Hell. They have hearts that they do not understand with. They have eyes they do not see with. They have ears they do not hear with. Such people are like cattle. No, they are even further astray. They are the unaware. 7:179



Remember your Lord in yourself humbly and fearfully without loudness of voice, morning and evening. Do not be of the unaware. 7:205